Code hangs when calling stop, restart, add/remove_handler

You tried to .stop(), .restart(), .add_handler() or .remove_handler() inside a running handler, but that can’t be done because the way Hydrogram deals with handlers would make it hang.

When calling one of the methods above inside an event handler, Hydrogram needs to wait for all running handlers to finish in order to continue. Since your handler is blocking the execution by waiting for the called method to finish and since Hydrogram needs to wait for your handler to finish, you are left with a deadlock.

The solution to this problem is to pass block=False to such methods so that they return immediately and the actual code called asynchronously.