Hi,
dispite the fact that this output reminds me at these ugly Java stacktraces, the very first line says much:
'Dist::Zilla::Role::File' requires the methods 'encoded_content' and '
+encoding' to be implemented by 'Dist::Zilla::File::Generated'
Without knowing the details, but Dist::Zilla::File::Generated is from 2012 and Dist::Zilla has undergone many many changes since that time. I'm pretty sure that Dist::Zilla::File::Generated doesn't fulfill the API of current Dist::Zilla anymore. Probably you can replace that plugin.
Regards
McA