Since the client software has crashed, this means it didn't have time to release the token. In most cases, you won't even notice the problem, as the action of running the same client again will lead to an automatic token release, thanks to the present token files.

Try to retrieve all token files used by the crash and copy them in the right directories. You may force a token release with the corresponding token file (just be sure that the corresponding calculation has not run yet).

And if this release fails, you simply need to shutdown the license server and run it again.