_pickle.unpicklingerror: Could Not Find Mark

I got exceptions like UnicodeDecodeError raised when pickling (a list of) objects of EventFrame with a member participants that was an empty set. class EventFrame: '''Frame for

Solution 1:

The error _pickle.UnpicklingError: could not find MARK is raised because the offset of the file is not in the beginning. The solution is to call f.seek(0) before loading the pickle.

Solution 2:

I got this error at first _pickle.UnpicklingError: could not find MARK, but that was because I was using the class name in the module name. Once I removed it, it worked like a charm!