This is due to physical hardware changes specifically hard drives being swapped which seems to disassociate the license.
You'll want to go to the Bentley License management tool:
"C:\Program Files\Bentley\ProjectWise\bin" for example
Register Bentley
The license server should automatically populate
Go through the defaults
Select sign in later
and then the trials should be set
Then you should now be able to activate the licenses for Bentley.