diff --git a/integration/lsp/ivy_spec.ts b/integration/lsp/ivy_spec.ts
index 3ce5078873..0eceb51ee8 100644
--- a/integration/lsp/ivy_spec.ts
+++ b/integration/lsp/ivy_spec.ts
@@ -11,18 +11,19 @@ import * as lsp from 'vscode-languageserver-protocol';
 
 import {NgccComplete, ProjectLanguageService, ProjectLanguageServiceParams, RunNgcc, RunNgccParams} from '../../common/notifications';
 
-import {APP_COMPONENT, createConnection, initializeServer, openTextDocument} from './test_utils';
+import {APP_COMPONENT, createConnection, FOO_TEMPLATE, initializeServer, openTextDocument} from './test_utils';
 
 describe('Angular Ivy language server', () => {
   jasmine.DEFAULT_TIMEOUT_INTERVAL = 10000; /* 10 seconds */
 
   let client: MessageConnection;
 
-  beforeEach(() => {
+  beforeEach(async () => {
     client = createConnection({
       ivy: true,
     });
     client.listen();
+    await initializeServer(client);
   });
 
   afterEach(() => {
@@ -30,28 +31,24 @@ describe('Angular Ivy language server', () => {
   });
 
   it('should send ngcc notification after a project has finished loading', async () => {
-    await initializeServer(client);
     openTextDocument(client, APP_COMPONENT);
     const configFilePath = await onRunNgccNotification(client);
     expect(configFilePath.endsWith('integration/project/tsconfig.json')).toBeTrue();
   });
 
   it('should disable language service until ngcc has completed', async () => {
-    await initializeServer(client);
     openTextDocument(client, APP_COMPONENT);
     const languageServiceEnabled = await onLanguageServiceStateNotification(client);
     expect(languageServiceEnabled).toBeFalse();
   });
 
   it('should re-enable language service once ngcc has completed', async () => {
-    await initializeServer(client);
     openTextDocument(client, APP_COMPONENT);
     const languageServiceEnabled = await waitForNgcc(client);
     expect(languageServiceEnabled).toBeTrue();
   });
 
   it('should handle hover on inline template', async () => {
-    await initializeServer(client);
     openTextDocument(client, APP_COMPONENT);
     const languageServiceEnabled = await waitForNgcc(client);
     expect(languageServiceEnabled).toBeTrue();
@@ -66,6 +63,23 @@ describe('Angular Ivy language server', () => {
       value: '(property) AppComponent.name: string',
     });
   });
+
+  it('should show existing diagnostics on external template', async () => {
+    client.sendNotification(lsp.DidOpenTextDocumentNotification.type, {
+      textDocument: {
+        uri: `file://${FOO_TEMPLATE}`,
+        languageId: 'typescript',
+        version: 1,
+        text: `{{ doesnotexist }}`,
+      },
+    });
+    const languageServiceEnabled = await waitForNgcc(client);
+    expect(languageServiceEnabled).toBeTrue();
+    const diagnostics = await getDiagnosticsForFile(client, FOO_TEMPLATE);
+    expect(diagnostics.length).toBe(1);
+    expect(diagnostics[0].message)
+        .toBe(`Property 'doesnotexist' does not exist on type 'FooComponent'.`);
+  });
 });
 
 function onRunNgccNotification(client: MessageConnection): Promise<string> {
@@ -84,6 +98,18 @@ function onLanguageServiceStateNotification(client: MessageConnection): Promise<
   });
 }
 
+function getDiagnosticsForFile(
+    client: MessageConnection, fileName: string): Promise<lsp.Diagnostic[]> {
+  return new Promise(resolve => {
+    client.onNotification(
+        lsp.PublishDiagnosticsNotification.type, (params: lsp.PublishDiagnosticsParams) => {
+          if (params.uri === `file://${fileName}`) {
+            resolve(params.diagnostics);
+          }
+        });
+  });
+}
+
 async function waitForNgcc(client: MessageConnection): Promise<boolean> {
   const configFilePath = await onRunNgccNotification(client);
   // We run ngcc before the test, so no need to do anything here.
diff --git a/server/src/session.ts b/server/src/session.ts
index f464b46303..8511ee0e08 100644
--- a/server/src/session.ts
+++ b/server/src/session.ts
@@ -15,7 +15,7 @@ import * as notification from '../common/notifications';
 import {tsCompletionEntryToLspCompletionItem} from './completion';
 import {tsDiagnosticToLspDiagnostic} from './diagnostic';
 import {ServerHost} from './server_host';
-import {filePathToUri, lspPositionToTsPosition, lspRangeToTsPositions, tsTextSpanToLspRange, uriToFilePath} from './utils';
+import {filePathToUri, isConfiguredProject, lspPositionToTsPosition, lspRangeToTsPositions, tsTextSpanToLspRange, uriToFilePath} from './utils';
 
 export interface SessionOptions {
   host: ServerHost;
@@ -131,6 +131,25 @@ export class Session {
     // project as dirty to force update the graph.
     project.markAsDirty();
     this.info(`Enabling Ivy language service for ${project.projectName}.`);
+
+    // Send diagnostics since we skipped this step when opening the file
+    // (because language service was disabled while waiting for ngcc).
+    // First, make sure the Angular project is complete.
+    this.runGlobalAnalysisForNewlyLoadedProject(project);
+    project.refreshDiagnostics();  // Show initial diagnostics
+  }
+
+  /**
+   * Invoke the compiler for the first time so that external templates get
+   * matched to the project they belong to.
+   */
+  private runGlobalAnalysisForNewlyLoadedProject(project: ts.server.Project) {
+    if (!project.hasRoots()) {
+      return;
+    }
+    const fileName = project.getRootScriptInfos()[0].fileName;
+    // Getting semantic diagnostics will trigger a global analysis.
+    project.getLanguageService().getSemanticDiagnostics(fileName);
   }
 
   /**
@@ -293,7 +312,6 @@ export class Session {
           this.projectService.findProject(configFileName) :
           this.projectService.getScriptInfo(filePath)?.containingProjects.find(isConfiguredProject);
       if (!project) {
-        this.error(`Failed to find project for ${filePath}`);
         return;
       }
       if (project.languageServiceEnabled) {
@@ -553,7 +571,7 @@ export class Session {
       return;
     }
 
-    if (this.ivy && project instanceof ts.server.ConfiguredProject) {
+    if (this.ivy && isConfiguredProject(project)) {
       // Keep language service disabled until ngcc is completed.
       project.disableLanguageService();
       this.connection.sendNotification(notification.RunNgcc, {
@@ -594,7 +612,3 @@ export class Session {
     return false;
   }
 }
-
-function isConfiguredProject(project: ts.server.Project): project is ts.server.ConfiguredProject {
-  return project.projectKind === ts.server.ProjectKind.Configured;
-}
diff --git a/server/src/utils.ts b/server/src/utils.ts
index 28981c61b7..d070683afd 100644
--- a/server/src/utils.ts
+++ b/server/src/utils.ts
@@ -74,3 +74,8 @@ export function lspRangeToTsPositions(
   const end = lspPositionToTsPosition(scriptInfo, range.end);
   return [start, end];
 }
+
+export function isConfiguredProject(project: ts.server.Project):
+    project is ts.server.ConfiguredProject {
+  return project.projectKind === ts.server.ProjectKind.Configured;
+}