ERROR

Mechanical is opened > Workbench is automatically launched first > it sits on the loading screen for several minutes > it finally opens with the timeout connection error seen in this article this article‍ > you click ok > in the background (with no indication to you) it attempts to load mechanical for several minutes > you finally receive the error below and no tools appear in the toolbox.

Mechanical failed to open the database: The mechanical editor
does not have a valid license.  Please refer to the following directory
for more information:
C:\users\UserName\Appdata\Local\Temp\.ansys.

Software & Version

Mechanical / Workbench 2021 R2

*This example was taken from this version, but is not necessary limited to this version.

Description/Cause

This error was caused by a connection issue with the license server not having the License Server specified properly.

Solution

1. Verify your license server is specified correctly
2. If that does not work, follow, HOW TO - Test & Fix License Manager Connectivity Issues, to resolve all remaining connectivity issues. 
3. Open Mechanical, select File, then Licensing.  Click Reset to Default.   Close and try again.