diff --git a/app/client/src/api/Api.tsx b/app/client/src/api/Api.tsx
index 2566056cc8..bc1e208984 100644
--- a/app/client/src/api/Api.tsx
+++ b/app/client/src/api/Api.tsx
@@ -5,7 +5,7 @@ import {
   API_REQUEST_HEADERS,
 } from "constants/ApiConstants";
 import { ActionApiResponse } from "./ActionAPI";
-import { AUTH_LOGIN_URL } from "constants/routes";
+import { AUTH_LOGIN_URL, PAGE_NOT_FOUND_URL } from "constants/routes";
 import { setRouteBeforeLogin } from "utils/storage";
 import history from "utils/history";
 
@@ -66,6 +66,17 @@ axiosInstance.interceptors.response.use(
           });
         }
       }
+      if (
+        error.resonse.status === 404 &&
+        error.response.app_error_code === 4028
+      ) {
+        history.push(PAGE_NOT_FOUND_URL);
+        return Promise.reject({
+          code: 404,
+          message: "Page Not Found",
+          show: false,
+        });
+      }
       if (error.response.data.responseMeta) {
         return Promise.resolve(error.response.data);
       }
diff --git a/app/client/src/api/UserApi.tsx b/app/client/src/api/UserApi.tsx
index 2235230173..eb7baea265 100644
--- a/app/client/src/api/UserApi.tsx
+++ b/app/client/src/api/UserApi.tsx
@@ -65,6 +65,7 @@ class UserApi extends Api {
   static switchUserOrgURL = `${UserApi.usersURL}/switchOrganization`;
   static addOrgURL = `${UserApi.usersURL}/addOrganization`;
   static logoutURL = "v1/logout";
+  static currentUserURL = "v1/users/me";
 
   static createUser(
     request: CreateUserRequest,
@@ -76,6 +77,10 @@ class UserApi extends Api {
     return Api.get(UserApi.usersURL + "/" + request.id);
   }
 
+  static getCurrentUser(): AxiosPromise<ApiResponse> {
+    return Api.get(UserApi.currentUserURL);
+  }
+
   static forgotPassword(
     request: ForgotPasswordRequest,
   ): AxiosPromise<ApiResponse> {
diff --git a/app/client/src/assets/images/404-image.png b/app/client/src/assets/images/404-image.png
new file mode 100644
index 0000000000..cba759370c
Binary files /dev/null and b/app/client/src/assets/images/404-image.png differ
diff --git a/app/client/src/constants/ReduxActionConstants.tsx b/app/client/src/constants/ReduxActionConstants.tsx
index ebd86c5f7f..a3cfa4145c 100644
--- a/app/client/src/constants/ReduxActionConstants.tsx
+++ b/app/client/src/constants/ReduxActionConstants.tsx
@@ -216,6 +216,7 @@ export const ReduxActionTypes: { [key: string]: string } = {
   GET_ALL_APPLICATION_INIT: "GET_ALL_APPLICATION_INIT",
   FETCH_USER_APPLICATIONS_ORGS_SUCCESS: "FETCH_USER_APPLICATIONS_ORGS_SUCCESS",
   FETCH_USER_DETAILS_SUCCESS: "FETCH_USER_DETAILS_SUCCESS",
+  FETCH_USER_DETAILS_ERROR: "FETCH_USER_DETAILS_ERROR",
   FETCH_ALL_USERS_SUCCESS: "FETCH_ALL_USERS_SUCCESS",
   FETCH_ALL_USERS_INIT: "FETCH_ALL_USERS_INIT",
   FETCH_ALL_ROLES_SUCCESS: "FETCH_ALL_ROLES_SUCCESS",
diff --git a/app/client/src/constants/routes.ts b/app/client/src/constants/routes.ts
index 7b78575229..828b6d61d3 100644
--- a/app/client/src/constants/routes.ts
+++ b/app/client/src/constants/routes.ts
@@ -2,6 +2,7 @@ import { MenuIcons } from "icons/MenuIcons";
 
 export const BASE_URL = "/";
 export const ORG_URL = "/org";
+export const PAGE_NOT_FOUND_URL = "/404";
 export const APPLICATIONS_URL = `/applications`;
 export const BUILDER_URL = "/applications/:applicationId/pages/:pageId/edit";
 export const USER_AUTH_URL = "/user";
diff --git a/app/client/src/constants/userConstants.ts b/app/client/src/constants/userConstants.ts
index e3930dfe7a..ea0e91914d 100644
--- a/app/client/src/constants/userConstants.ts
+++ b/app/client/src/constants/userConstants.ts
@@ -1,3 +1,5 @@
+export const ANONYMOUS_USERNAME = "anonymousUser";
+
 export type User = {
   id: string;
   email: string;
diff --git a/app/client/src/index.tsx b/app/client/src/index.tsx
index a5be152258..ca2ebaecf5 100755
--- a/app/client/src/index.tsx
+++ b/app/client/src/index.tsx
@@ -23,6 +23,7 @@ import {
   BASE_LOGIN_URL,
   BASE_SIGNUP_URL,
   USERS_URL,
+  PAGE_NOT_FOUND_URL,
 } from "constants/routes";
 import { LayersContext, Layers } from "constants/Layers";
 
@@ -120,6 +121,11 @@ ReactDOM.render(
                 routeProtected
                 logDisable
               />
+              <AppRoute
+                path={PAGE_NOT_FOUND_URL}
+                component={PageNotFound}
+                name={"PageNotFound"}
+              />
               <AppRoute component={PageNotFound} name={"PageNotFound"} />
             </Switch>
           </Suspense>
diff --git a/app/client/src/pages/Applications/ApplicationCard.tsx b/app/client/src/pages/Applications/ApplicationCard.tsx
index d37f429d6e..5ead4c9a29 100644
--- a/app/client/src/pages/Applications/ApplicationCard.tsx
+++ b/app/client/src/pages/Applications/ApplicationCard.tsx
@@ -12,7 +12,6 @@ import {
   theme,
   getBorderCSSShorthand,
   getColorWithOpacity,
-  Theme,
 } from "constants/DefaultTheme";
 import ContextDropdown, {
   ContextDropdownOption,
diff --git a/app/client/src/pages/Applications/index.tsx b/app/client/src/pages/Applications/index.tsx
index 27b86bc1f9..8d59ba08c0 100644
--- a/app/client/src/pages/Applications/index.tsx
+++ b/app/client/src/pages/Applications/index.tsx
@@ -26,9 +26,7 @@ import { PERMISSION_TYPE, isPermitted } from "./permissionHelpers";
 import { MenuIcons } from "icons/MenuIcons";
 import { DELETING_APPLICATION } from "constants/messages";
 import { AppToaster } from "components/editorComponents/ToastComponent";
-import AnalyticsUtil from "utils/AnalyticsUtil";
 import FormDialogComponent from "components/editorComponents/form/FormDialogComponent";
-import OrganizationListMockResponse from "mockResponses/OrganisationListResponse";
 import { User } from "constants/userConstants";
 import CustomizedDropdown, {
   CustomizedDropdownProps,
@@ -107,7 +105,6 @@ const StyledDialog = styled(Dialog)<{ setMaxWidth?: boolean }>`
 
 type ApplicationProps = {
   applicationList: ApplicationPayload[];
-  fetchApplications: () => void;
   createApplication: (appName: string) => void;
   isCreatingApplication: boolean;
   isFetchingApplications: boolean;
@@ -319,8 +316,6 @@ const mapStateToProps = (state: AppState) => ({
 });
 
 const mapDispatchToProps = (dispatch: any) => ({
-  fetchApplications: () =>
-    dispatch({ type: ReduxActionTypes.FETCH_APPLICATION_LIST_INIT }),
   getAllApplication: () =>
     dispatch({ type: ReduxActionTypes.GET_ALL_APPLICATION_INIT }),
   createApplication: (appName: string) => {
diff --git a/app/client/src/pages/common/PageHeader.tsx b/app/client/src/pages/common/PageHeader.tsx
index 83dd75f4bb..a9dbddf436 100644
--- a/app/client/src/pages/common/PageHeader.tsx
+++ b/app/client/src/pages/common/PageHeader.tsx
@@ -1,15 +1,18 @@
 import React from "react";
+import { useHistory, Link } from "react-router-dom";
 import { connect } from "react-redux";
 import { getCurrentUser } from "selectors/usersSelectors";
-import { getOrgs, getCurrentOrg } from "selectors/organizationSelectors";
 import styled from "styled-components";
 import StyledHeader from "components/designSystems/appsmith/StyledHeader";
 import CustomizedDropdown from "./CustomizedDropdown";
 import DropdownProps from "./CustomizedDropdown/HeaderDropdownData";
 import { AppState } from "reducers";
-import { Org } from "constants/orgConstants";
-import { User } from "constants/userConstants";
+import { User, ANONYMOUS_USERNAME } from "constants/userConstants";
 import Logo from "assets/images/appsmith_logo.png";
+import { ReduxActionTypes } from "constants/ReduxActionConstants";
+import { useEffect } from "react";
+import { AUTH_LOGIN_URL, APPLICATIONS_URL } from "constants/routes";
+import Button from "components/editorComponents/Button";
 
 const StyledPageHeader = styled(StyledHeader)`
   width: 100%;
@@ -28,31 +31,47 @@ const LogoContainer = styled.div`
 `;
 
 type PageHeaderProps = {
-  orgs?: Org[];
-  currentOrg?: Org;
   user?: User;
+  fetchCurrentUser: () => void;
 };
 
 export const PageHeader = (props: PageHeaderProps) => {
-  const { user } = props;
+  const { user, fetchCurrentUser } = props;
+  const history = useHistory();
+  useEffect(() => {
+    fetchCurrentUser();
+  }, [fetchCurrentUser]);
+
   return (
     <StyledPageHeader>
       <LogoContainer>
-        <a href="/applications">
+        <Link to={APPLICATIONS_URL}>
           <img className="logoimg" src={Logo} alt="Appsmith Logo" />
-        </a>
+        </Link>
       </LogoContainer>
       <StyledDropDownContainer>
-        {user && <CustomizedDropdown {...DropdownProps(user, user.username)} />}
+        {user && user.username !== ANONYMOUS_USERNAME ? (
+          <CustomizedDropdown {...DropdownProps(user, user.username)} />
+        ) : (
+          <Button
+            filled
+            text="Sign In"
+            intent={"primary"}
+            size="small"
+            onClick={() => history.push(AUTH_LOGIN_URL)}
+          />
+        )}
       </StyledDropDownContainer>
     </StyledPageHeader>
   );
 };
 
 const mapStateToProps = (state: AppState) => ({
-  currentOrg: getCurrentOrg(state),
   user: getCurrentUser(state),
-  orgs: getOrgs(state),
 });
 
-export default connect(mapStateToProps, null)(PageHeader);
+const mapDispatchToProps = (dispatch: any) => ({
+  fetchCurrentUser: () => dispatch({ type: ReduxActionTypes.FETCH_USER_INIT }),
+});
+
+export default connect(mapStateToProps, mapDispatchToProps)(PageHeader);
diff --git a/app/client/src/pages/common/PageNotFound.tsx b/app/client/src/pages/common/PageNotFound.tsx
index d6ff1b6453..597cff16d5 100644
--- a/app/client/src/pages/common/PageNotFound.tsx
+++ b/app/client/src/pages/common/PageNotFound.tsx
@@ -1,45 +1,56 @@
 import React from "react";
-import styled from "styled-components";
-import { NonIdealState, Button, Card, Elevation } from "@blueprintjs/core";
 import { RouterProps } from "react-router";
+import styled from "styled-components";
+import Button from "components/editorComponents/Button";
+import PageUnavailableImage from "assets/images/404-image.png";
+import PageHeader from "pages/common/PageHeader";
+import { BASE_URL } from "constants/routes";
 
-const NotFoundPageWrapper = styled.div`
-  width: 100vw;
-  height: 100vh;
-  display: flex;
-  justify-content: center;
-  align-items: center;
-`;
-const Title = styled.div`
-  font-size: ${props => props.theme.fontSizes[10]}px;
+const Wrapper = styled.div`
   text-align: center;
+  margin-top: 5%;
+  .bold-text {
+    font-weight: ${props => props.theme.fontWeights[3]};
+    font-size: 24px;
+  }
+  .page-unavailable-img {
+    width: 35%;
+  }
+  .button-position {
+    margin: auto;
+  }
 `;
+
 class PageNotFound extends React.PureComponent<RouterProps> {
   public render() {
     return (
-      <NotFoundPageWrapper>
-        <Card elevation={Elevation.TWO}>
-          <Title>
-            <span role="img" aria-label="Page Not Found">
-              🙊
-            </span>
-          </Title>
-          <NonIdealState
-            description={
-              "We didn't mean for you to reach this page. Let's find your way back to building awesome applications."
-            }
-            action={
-              <Button
-                onClick={() => {
-                  this.props.history.push("/");
-                }}
-              >
-                {"Home"}
-              </Button>
-            }
-          />
-        </Card>
-      </NotFoundPageWrapper>
+      <>
+        <PageHeader />
+        <Wrapper>
+          <img
+            src={PageUnavailableImage}
+            alt="Page Unavailable"
+            className="page-unavailable-img"
+          ></img>
+          <div>
+            <p className="bold-text">Page not found</p>
+            <p>
+              Either this page doesn't exist, or you don't have access to <br />
+              this page.
+            </p>
+            <Button
+              filled
+              text="Go back to homepage"
+              intent="primary"
+              icon="arrow-right"
+              iconAlignment="right"
+              size="small"
+              className="button-position"
+              onClick={() => this.props.history.push(BASE_URL)}
+            />
+          </div>
+        </Wrapper>
+      </>
     );
   }
 }
diff --git a/app/client/src/pages/organization/settings.tsx b/app/client/src/pages/organization/settings.tsx
index 3f44772193..29b39bb03b 100644
--- a/app/client/src/pages/organization/settings.tsx
+++ b/app/client/src/pages/organization/settings.tsx
@@ -23,6 +23,7 @@ import FormDialogComponent from "components/editorComponents/form/FormDialogComp
 import { getCurrentUser } from "selectors/usersSelectors";
 import { User } from "constants/userConstants";
 import { useTable, useFlexLayout } from "react-table";
+
 type OrgProps = {
   allOrgs: Organization[];
   changeOrgName: (value: string) => void;
@@ -51,6 +52,8 @@ type DropdownProps = {
   activeItem: string;
   userRoles: object;
   username: string;
+  changeOrgUserRole: (orgId: string, role: string, username: string) => void;
+  orgId: string;
 };
 
 const StyledDropDown = styled.div`
@@ -79,6 +82,90 @@ const StyledMenu = styled(Menu)`
   }
 `;
 
+const RoleNameCell = (props: any) => {
+  const {
+    roleName,
+    roles,
+    username,
+    isCurrentUser,
+    isChangingRole,
+  } = props.cellProps.row.original;
+
+  if (isCurrentUser) {
+    return <div>{roleName}</div>;
+  }
+
+  return (
+    <Popover
+      content={
+        <Dropdown
+          activeItem={roleName}
+          userRoles={roles}
+          username={username}
+          changeOrgUserRole={props.changeOrgUserRole}
+          orgId={props.orgId}
+        />
+      }
+      position={Position.BOTTOM_LEFT}
+    >
+      <StyledDropDown>
+        {roleName}
+        <Icon icon="chevron-down" />
+        {isChangingRole ? <Spinner size={20} /> : undefined}
+      </StyledDropDown>
+    </Popover>
+  );
+};
+
+const DeleteActionCell = (props: any) => {
+  const { username, isCurrentUser, isDeleting } = props.cellProps.row.original;
+
+  return (
+    !isCurrentUser &&
+    (isDeleting ? (
+      <Spinner size={20} />
+    ) : (
+      <FormIcons.DELETE_ICON
+        height={20}
+        width={20}
+        color={"grey"}
+        background={"grey"}
+        onClick={() => props.deleteOrgUser(props.orgId, username)}
+        style={{ alignSelf: "center", cursor: "pointer" }}
+      />
+    ))
+  );
+};
+
+const Dropdown = (props: DropdownProps) => {
+  return (
+    <StyledMenu>
+      {Object.entries(props.userRoles).map((role, index) => {
+        const MenuContent = (
+          <div>
+            <span>
+              <b>{role[0]}</b>
+            </span>
+            <div>{role[1]}</div>
+          </div>
+        );
+
+        return (
+          <MenuItem
+            multiline
+            key={index}
+            onClick={() =>
+              props.changeOrgUserRole(props.orgId, role[0], props.username)
+            }
+            active={props.activeItem === role[0]}
+            text={MenuContent}
+          />
+        );
+      })}
+    </StyledMenu>
+  );
+};
+
 export const OrgSettings = (props: PageProps) => {
   const {
     match: {
@@ -97,43 +184,7 @@ export const OrgSettings = (props: PageProps) => {
     roles: props.allRole,
     isCurrentUser: user.username === props.currentUser?.username,
   }));
-  const data = React.useMemo(() => userTableData, [
-    props.allUsers,
-    props.allRole,
-  ]);
-
-  const RoleNameCell = (cellProps: any) => {
-    const {
-      roleName,
-      roles,
-      username,
-      isCurrentUser,
-      isChangingRole,
-    } = cellProps.row.original;
-
-    if (isCurrentUser) {
-      return <div>{roleName}</div>;
-    }
-
-    return (
-      <Popover
-        content={
-          <Dropdown
-            activeItem={roleName}
-            userRoles={roles}
-            username={username}
-          />
-        }
-        position={Position.BOTTOM_LEFT}
-      >
-        <StyledDropDown>
-          {roleName}
-          <Icon icon="chevron-down" />
-          {isChangingRole ? <Spinner size={20} /> : undefined}
-        </StyledDropDown>
-      </Popover>
-    );
-  };
+  const data = React.useMemo(() => userTableData, [userTableData]);
 
   const columns = React.useMemo(() => {
     return [
@@ -148,37 +199,19 @@ export const OrgSettings = (props: PageProps) => {
       {
         Header: "Role",
         accessor: "roleName",
-        Cell: RoleNameCell,
+        Cell: (cellProps: any) => {
+          return RoleNameCell({ cellProps, changeOrgUserRole, orgId });
+        },
       },
       {
         Header: "Delete",
         accessor: "delete",
         Cell: (cellProps: any) => {
-          const {
-            username,
-            isCurrentUser,
-            isDeleting,
-          } = cellProps.row.original;
-
-          return (
-            !isCurrentUser &&
-            (isDeleting ? (
-              <Spinner size={20} />
-            ) : (
-              <FormIcons.DELETE_ICON
-                height={20}
-                width={20}
-                color={"grey"}
-                background={"grey"}
-                onClick={() => deleteOrgUser(orgId, username)}
-                style={{ alignSelf: "center", cursor: "pointer" }}
-              />
-            ))
-          );
+          return DeleteActionCell({ cellProps, deleteOrgUser, orgId });
         },
       },
     ];
-  }, [props.allUsers, props.allRole]);
+  }, [orgId, deleteOrgUser, changeOrgUserRole]);
 
   const currentOrg = allOrgs.find(org => org.organization.id === orgId);
   const currentOrgName = currentOrg?.organization.name ?? "";
@@ -203,33 +236,6 @@ export const OrgSettings = (props: PageProps) => {
     getAllApplication();
   }, [orgId, fetchUser, fetchAllRoles, getAllApplication]);
 
-  const Dropdown = (props: DropdownProps) => {
-    return (
-      <StyledMenu>
-        {Object.entries(props.userRoles).map((role, index) => {
-          const MenuContent = (
-            <div>
-              <span>
-                <b>{role[0]}</b>
-              </span>
-              <div>{role[1]}</div>
-            </div>
-          );
-
-          return (
-            <MenuItem
-              multiline
-              key={index}
-              onClick={() => changeOrgUserRole(orgId, role[0], props.username)}
-              active={props.activeItem === role[0]}
-              text={MenuContent}
-            />
-          );
-        })}
-      </StyledMenu>
-    );
-  };
-
   return (
     <React.Fragment>
       <PageSectionHeader>
diff --git a/app/client/src/reducers/uiReducers/applicationsReducer.tsx b/app/client/src/reducers/uiReducers/applicationsReducer.tsx
index c4e45eff04..1a9408bd0e 100644
--- a/app/client/src/reducers/uiReducers/applicationsReducer.tsx
+++ b/app/client/src/reducers/uiReducers/applicationsReducer.tsx
@@ -7,7 +7,6 @@ import {
 } from "constants/ReduxActionConstants";
 import { Organization } from "constants/orgConstants";
 import { ERROR_MESSAGE_CREATE_APPLICATION } from "constants/messages";
-import { getApplicationPayload } from "mockComponentProps/ApplicationPayloads";
 
 const initialState: ApplicationsReduxState = {
   isFetchingApplications: false,
diff --git a/app/client/src/reducers/uiReducers/orgReducer.ts b/app/client/src/reducers/uiReducers/orgReducer.ts
index 31cc972c9d..4d8d7b4f11 100644
--- a/app/client/src/reducers/uiReducers/orgReducer.ts
+++ b/app/client/src/reducers/uiReducers/orgReducer.ts
@@ -104,7 +104,7 @@ const orgReducer = createReducer(initialState, {
     action: ReduxAction<{ username: string }>,
   ) => {
     const _orgUsers = state.orgUsers.map((user: OrgUser) => {
-      if (user.username == action.payload.username) {
+      if (user.username === action.payload.username) {
         return {
           ...user,
           isChangingRole: true,
@@ -119,7 +119,7 @@ const orgReducer = createReducer(initialState, {
     action: ReduxAction<{ username: string }>,
   ) => {
     const _orgUsers = state.orgUsers.map((user: OrgUser) => {
-      if (user.username == action.payload.username) {
+      if (user.username === action.payload.username) {
         return {
           ...user,
           isDeleting: true,
diff --git a/app/client/src/sagas/ApplicationSagas.tsx b/app/client/src/sagas/ApplicationSagas.tsx
index 20b76917a1..c80e6096f4 100644
--- a/app/client/src/sagas/ApplicationSagas.tsx
+++ b/app/client/src/sagas/ApplicationSagas.tsx
@@ -83,10 +83,6 @@ export function* getAllApplicationSaga() {
         type: ReduxActionTypes.FETCH_USER_APPLICATIONS_ORGS_SUCCESS,
         payload: organizationApplication,
       });
-      yield put({
-        type: ReduxActionTypes.FETCH_USER_DETAILS_SUCCESS,
-        payload: response.data.user,
-      });
     }
   } catch (error) {
     yield put({
diff --git a/app/client/src/sagas/userSagas.tsx b/app/client/src/sagas/userSagas.tsx
index f3a02f6a2f..0fdc976a84 100644
--- a/app/client/src/sagas/userSagas.tsx
+++ b/app/client/src/sagas/userSagas.tsx
@@ -72,6 +72,27 @@ export function* createUserSaga(
   }
 }
 
+export function* getCurrentUserSaga() {
+  try {
+    const response: ApiResponse = yield call(UserApi.getCurrentUser);
+
+    const isValidResponse = yield validateResponse(response);
+    if (isValidResponse) {
+      yield put({
+        type: ReduxActionTypes.FETCH_USER_DETAILS_SUCCESS,
+        payload: response.data,
+      });
+    }
+  } catch (error) {
+    yield put({
+      type: ReduxActionErrorTypes.FETCH_USER_DETAILS_ERROR,
+      payload: {
+        error,
+      },
+    });
+  }
+}
+
 export function* forgotPasswordSaga(
   action: ReduxActionWithPromise<ForgotPasswordRequest>,
 ) {
@@ -326,6 +347,7 @@ export function* logoutSaga() {
 export default function* userSagas() {
   yield all([
     takeLatest(ReduxActionTypes.CREATE_USER_INIT, createUserSaga),
+    takeLatest(ReduxActionTypes.FETCH_USER_INIT, getCurrentUserSaga),
     takeLatest(ReduxActionTypes.FORGOT_PASSWORD_INIT, forgotPasswordSaga),
     takeLatest(ReduxActionTypes.RESET_USER_PASSWORD_INIT, resetPasswordSaga),
     takeLatest(