Error: Cannot Run External Application "Librarian"

Several users have complained about a persistent error when launching the Librarian. The most common reason for this error is the inability of the App to write into the Windows user profile folder.

Reason for the Error:

Microsoft Ransomware Protection through the 'Protected Folders'  is enabled. This prevents the App from accessing the user profile to Cache Library Data.


Two possible solutions exist:
1. Disable Controlled Folder Access Control or
2. Create Exceptions (can be tedious) to allow access to the following location:


Below are screenshots of the Windows Security User Interface leading to the Controlled Access folder: