Analysing the code, I think that you must have a combination of three things:
1) Another third-party plugin installed which uses the same library as we do for accessing updates; but a different version.
2) Something which loads the “debug bar” extension for that class.
3) Apparently something which intercepts all errors and aborts WP if they occur and shows them on the screen instead.
I’d suggest de-activating other third-party plugins, updating, and then activating them one-by-one in order to identify the culprit.
David