Chrome launches with error; only the close button works.

Uninstall and reinstall the updated version of Chrome.

Yes, I am currently using Microsoft 365 E3, Premium, and Standard, and I am the administrator.

It seems I may have accidentally messed up the administrator settings.

Thank you for sharing your detail information with me.

Based on the error message that you provided, the message "The system administrator has blocked this app. For more details, please contact your system administrator" appears when you try to run Chrome.

Even though you are the administrator, this means the block is coming from an application control policy, not from Microsoft 365 licensing.

The restriction is almost certainly enforced by one of the following controls configured on the device or via policy.

Possible cause

Application control policies apply before admin privileges are evaluated.

So even a local or domain administrator cannot bypass:

• AppLocker

Reference: AppLocker | Microsoft Learn

• Software Restriction Policies (SRP)

Reference: Administer Software Restriction Policies | Microsoft Learn

• Microsoft Defender Application Control (WDAC / MDAC)

Reference: WDAC enforced infrastructure in Windows Admin Center | Microsoft Learn

• SmartScreen / Attack Surface Reduction (ASR)

If Chrome is not explicitly allowed, Windows will block it and show exactly this message.

Identify

• Check AppLocker

1. Press Win + R → type secpol.msc
2. Go to: Application Control Policies → AppLocker
3. Check these rules below:

Executable Rules, Windows Installer Rules and Script Rules

If enforcement is Enabled and Chrome’s path or publisher is not allowed, it will be blocked.

Note: Chrome usually installs to C:\Program Files\Google\Chrome\Application\chrome.exe

• Check Software Restriction Policies (SRP)

1. In Local Security Policy (secpol.msc)
2. Go to: Security Settings → Software Restriction Policies
3. If SRP exists, check Additional Rules and Default Security Level

If the default is Disallowed, Chrome must have an explicit allow rule.

• Check WDAC / MDAC (Application Control)

If you are using Defender Application Control, Chrome will be blocked unless it is signed by an allowed publisher and the policy explicitly trusts it

To confirm WDAC as the path below and look for block events referencing chrome.exe

Check Event Viewer → Applications and Services Logs → Microsoft → Windows → CodeIntegrity

• Check SmartScreen / ASR

SmartScreen usually shows a warning, not a hard block. But ASR rules can hard-block apps. You can check: Microsoft Defender → Attack Surface Reduction rules and Intune or local Defender policy

Workaround

1. If using AppLocker

Create an allow rule for Chrome, best option: Publisher rule

• Allows future Chrome updates automatically
• Publisher: Google LLC
• Product: Google Chrome

Alternative: Path rule

• Allow C:\Program Files\Google\Chrome*

2. If using SRP

Add an Additional Rule allowing:

• Path: C:\Program Files\Google\Chrome*
• Or hash rule for chrome.exe

3. If using WDAC / MDAC

• Update the WDAC policy to trust, Google Chrome publisher certificate
• Re-deploy the policy and reboot

Note: WDAC changes always require a reboot

Thank you for reaching out on the Microsoft Q&A Forum!  

I hope this information can help you. Wish you have a pleasant day.