"We are unable to show Dynamics 365 App for Outlook because current user role does not have required permissions" error occurs in the Dynamics 365 App for Outlook

When you open the Dynamics 365 App for Outlook, you see the following error:

"We're sorry

We are unable to show Dynamics 365 App for Outlook because current user role does not have required permissions. Please contact your administrator to have required security role assigned to the Dynamics 365 App for Outlook solution."

If you click Show more, the additional details include the following info:

"Error: Don't have permissions to retrieve AppforOutlookModule id

Trace: Error: Don't have permissions to retrieve AppforOutlookModule id at new ..."

This error appears if your Dynamics 365 security role does not have access to the app module used by the Dynamics 365 App for Outlook.

Verify your Dynamics 365 security role has sufficient access to load the app module used by the Dynamics 365 App for Outlook.

1. Verify your security role has access to the Dynamics 365 App for Outlook app module:

https://docs.microsoft.com/dynamics365/customer-engagement/outlook-app/deploy-dynamics-365-app-for-outlook#provide-security-role-access

2. Refer to the following documentation for the required privileges to use the App for Outlook:

https://support.microsoft.com/help/4563997

3. After verifying all required privileges, close and reopen Outlook.