Do not fail while parsing illegal dates. Return None instead.

plexapi/utils.py

@@ -176,7 +176,11 @@ def toDatetime(value, format=None):
     """
     if value and value is not None:
         if format:
+            try:
                 value = datetime.strptime(value, format)
+            except ValueError:
+                # parsing failed
+                return None
         else:
             # https://bugs.python.org/issue30684
             # And platform support for before epoch seems to be flaky.