If a worker is fired then. How can I make sure that the data is not sabotaged?
What type of files are they and where are they stored?
1. there should be backups.
2. When the employee is fired, they are not in the building, the locks have been changed, their network access has been removed...etc.
Describe the mechanics of the threat, and I'm sure there will be some ideas. The current question does not provide enough details to allow for a more detailed response.
The answer is simple - block him/her -keep him/her out.
I hope the employee dismissal was fair.
If you mean with regards to Grabcad access, in the Workbench 'users' tab you have the option to deactivate or remove the user.