How to fix the "NotImlementedError"

[erikpuot-cmd]

was working fine, was downloading no problem and then it started throwing me the below error. I changed nothing and its giving me this for every URL i try to give it. Any help would be appreciated.

NotImplementedError: Mutagen type <class 'NoneType'> not implemented

[Googolplexed0]

NotImplementedError: Mutagen type <class 'NoneType'> not implemented

Take a look at my fork, this error does not occur there. If you can actually reproduce it there, I'd be happy to fix it.