diff --git a/Extension/src/common.ts b/Extension/src/common.ts
index 712197b085..adc66eed2a 100644
--- a/Extension/src/common.ts
+++ b/Extension/src/common.ts
@@ -534,6 +534,20 @@ export function checkInstallLockFile(): Promise<boolean> {
     return checkFileExists(getInstallLockPath());
 }
 
+/** Get the platform that the installed binaries belong to.*/
+export function getInstalledBinaryPlatform(): string | undefined {
+    // the LLVM/bin folder is utilized to identify the platform
+    let installedPlatform: string = "";
+    if (checkFileExistsSync(path.join(extensionPath, "LLVM/bin/clang-format.exe"))) {
+        installedPlatform = "win32";
+    } else if (checkFileExistsSync(path.join(extensionPath, "LLVM/bin/clang-format.darwin"))) {
+        installedPlatform = "darwin";
+    } else if (checkFileExistsSync(path.join(extensionPath, "LLVM/bin/clang-format"))) {
+        installedPlatform = "linux";
+    }
+    return installedPlatform;
+}
+
 /** Reads the content of a text file */
 export function readFileText(filePath: string, encoding: string = "utf8"): Promise<string> {
     return new Promise<string>((resolve, reject) => {
diff --git a/Extension/src/githubAPI.ts b/Extension/src/githubAPI.ts
index 048ff33b09..5ebe4f113f 100644
--- a/Extension/src/githubAPI.ts
+++ b/Extension/src/githubAPI.ts
@@ -12,7 +12,7 @@ import * as vscode from 'vscode';
 import * as telemetry from './telemetry';
 
 const testingInsidersVsixInstall: boolean = false; // Change this to true to enable testing of the Insiders vsix installation.
-
+export const releaseDownloadUrl: string = "https://github.com/microsoft/vscode-cpptools/releases";
 /**
  * The object representation of a Build Asset. Each Asset corresponds to information about a release file on GitHub.
  */
@@ -96,7 +96,7 @@ function isArrayOfBuilds(input: any): input is Build[] {
  * @param info Information about the user's operating system.
  * @return VSIX filename for the extension's releases matched to the user's platform.
  */
-function vsixNameForPlatform(info: PlatformInformation): string {
+export function vsixNameForPlatform(info: PlatformInformation): string {
     const vsixName: string | undefined = function(platformInfo): string | undefined {
         switch (platformInfo.platform) {
             case 'win32': return 'cpptools-win32.vsix';
diff --git a/Extension/src/main.ts b/Extension/src/main.ts
index d5aab4c5ea..a085276d27 100644
--- a/Extension/src/main.ts
+++ b/Extension/src/main.ts
@@ -17,12 +17,13 @@ import { PersistentState } from './LanguageServer/persistentState';
 
 import { CppToolsApi, CppToolsExtension } from 'vscode-cpptools';
 import { getTemporaryCommandRegistrarInstance, initializeTemporaryCommandRegistrar } from './commands';
-import { PlatformInformation } from './platform';
+import { PlatformInformation, GetOSName } from './platform';
 import { PackageManager, PackageManagerError, IPackage, VersionsMatch, ArchitecturesMatch, PlatformsMatch } from './packageManager';
 import { getInstallationInformation, InstallationInformation, setInstallationStage, setInstallationType, InstallationType } from './installationInformation';
 import { Logger, getOutputChannelLogger, showOutputChannel } from './logger';
 import { CppTools1, NullCppTools } from './cppTools1';
 import { CppSettings } from './LanguageServer/settings';
+import { vsixNameForPlatform, releaseDownloadUrl } from './githubAPI';
 
 nls.config({ messageFormat: nls.MessageFormat.bundle, bundleFormat: nls.BundleFormat.standalone })();
 const localize: nls.LocalizeFunc = nls.loadMessageBundle();
@@ -49,6 +50,20 @@ export async function activate(context: vscode.ExtensionContext): Promise<CppToo
     Telemetry.activate();
     util.setProgress(0);
 
+    // check if the correct offline/insiders vsix is installed on the correct platform
+    let installedPlatform: string | undefined = util.getInstalledBinaryPlatform();
+    if (!installedPlatform || (process.platform !== installedPlatform)) {
+        const platformInfo: PlatformInformation = await PlatformInformation.GetPlatformInformation();
+        const vsixName: string = vsixNameForPlatform(platformInfo);
+        errMsg = localize("native.binaries.not.supported", "This {0} version of the extension is incompatible with your OS. Please download and install the \"{1}\" version of the extension.", GetOSName(installedPlatform), vsixName);
+        const downloadLink: string = localize("download.button", "Go to Download Page");
+        vscode.window.showErrorMessage(errMsg, downloadLink).then(async (selection) => {
+            if (selection === downloadLink) {
+                vscode.env.openExternal(vscode.Uri.parse(releaseDownloadUrl));
+            }
+        });
+    }
+
     // Register a protocol handler to serve localized versions of the schema for c_cpp_properties.json
     class SchemaProvider implements vscode.TextDocumentContentProvider {
         public async provideTextDocumentContent(uri: vscode.Uri): Promise<string> {
@@ -317,7 +332,7 @@ function handleError(error: any): void {
     outputChannelLogger.appendLine(localize('failed.at.stage', "Failed at stage: {0}", installationInformation.stage));
     outputChannelLogger.appendLine(errorMessage);
     outputChannelLogger.appendLine("");
-    outputChannelLogger.appendLine(localize('failed.at.stage2', 'If you work in an offline environment or repeatedly see this error, try downloading a version of the extension with all the dependencies pre-included from https://github.com/Microsoft/vscode-cpptools/releases, then use the "Install from VSIX" command in VS Code to install it.'));
+    outputChannelLogger.appendLine(localize('failed.at.stage2', 'If you work in an offline environment or repeatedly see this error, try downloading a version of the extension with all the dependencies pre-included from {0}, then use the "Install from VSIX" command in VS Code to install it.', releaseDownloadUrl));
     showOutputChannel();
 }
 
diff --git a/Extension/src/platform.ts b/Extension/src/platform.ts
index 1f48c270ee..4e777c1e0e 100644
--- a/Extension/src/platform.ts
+++ b/Extension/src/platform.ts
@@ -14,6 +14,15 @@ import * as nls from 'vscode-nls';
 nls.config({ messageFormat: nls.MessageFormat.bundle, bundleFormat: nls.BundleFormat.standalone })();
 const localize: nls.LocalizeFunc = nls.loadMessageBundle();
 
+export function GetOSName(processPlatform: string | undefined): string | undefined {
+    switch (processPlatform) {
+        case "win32": return "Windows";
+        case "darwin": return "MacOS";
+        case "linux": return "Linux";
+        default: return undefined;
+    }
+}
+
 export class PlatformInformation {
     constructor(public platform: string, public architecture?: string, public distribution?: LinuxDistribution, public version?: string) { }