Blank page appears within Dynamics App for Outlook

When attempting to use the Dynamics 365 App for Outlook on Outlook desktop, you see a blank page instead of the application loading as expected.

Cause 1: This can occur if not all of the URLs used to authenticate and access Dynamics 365 are in the same Internet Explorer security zone.

Cause 2: This can occur if the LocalLow folder has an incorrect integrity level. The correct setting is to have the integrity level set to low as the folder name indicates.

Cause 3: This issue can occur if an issue is cached in Internet Explorer or Edge. If this was previously working but quit working recently, this is most likely the cause. 

Cause 4: Microsoft is aware of an issue that can occur under the following conditions:

•  You are using Windows 10 with update 1903 or higher
•  Your organization is configured to use Dynamics 365 Online with Exchange on-premises
•  You are using Office 365 ProPlus with a version prior to 1910

Resolution 1:

Use the steps in the following article to verify each of the necessary URLs are in the same Internet Explorer security zone.

https://support.microsoft.com/help/4035750

Resolution 2:

1. Open a command prompt.
2. Run the following command:

icacls %userprofile%\Appdata\LocalLow /t /setintegritylevel (OI)(CI)L

Resolution 3: 

If you are using Office 365 version 16.0.11629 and Windows 10 version 1903 or later, follow these steps as Office Add-ins are now using  Microsoft Edge WebView:

1. Install Microsoft Edge DevTools Preview
2. In Outlook, launch the Dynamics 365 app for Outlook
3. Run Microsoft Edge DevTools Preview
4. You should see Dynamics 365 (EXP) as a debug target
5. Click on it to launch the “F12” tools
6. Go to the “Console” tab
7. Run: window.localStorage.clear()
8. Open the app again in Outlook

If you are using early versions of Office 365 and Windows, use the steps in the following article to clear your Internet Explorer cache: 

https://support.microsoft.com/en-us/help/4345548

If you are using a Mac, refer to the following article:

https://docs.microsoft.com/office/dev/add-ins/testing/debug-office-add-ins-on-ipad-and-mac#clearing-the-office-applications-cache-on-a-mac

Resolution 4: 

If the conditions mentioned in Cause 4 are true, install Office update 1910 or later which includes a fix for this type of issue.