Failure on an End Event. Does not exist User...

Now that you have confirmed, let's see if the issue is indeed with your account:

1. Open the problematic model
2. Do a File - Save As to create a copy
3. Remove all node except for the START ---> END EVENT
4. Run a new instance. Does the same error occur?
5. If it doesn't occur, review the variables of the original process and find all variables that contain a username, take notes on them since they could be the ones generating the error.

Now that you have confirmed, let's see if the issue is indeed with your account:

1. Open the problematic model
2. Do a File - Save As to create a copy
3. Remove all node except for the START ---> END EVENT
4. Run a new instance. Does the same error occur?
5. If it doesn't occur, review the variables of the original process and find all variables that contain a username, take notes on them since they could be the ones generating the error.