Thread:Project:Support desk/Update previous MW 1.16.5 to 1.17.0 throws an 500 internal server error/reply (28)

You're going to have to be more specific. This thread is about at least 9 totally unrelated problems. (Actually it'd probably be best if you created a new thread, instead of adding to this one). I can't see anything wrong from a quick glance, other then you're missing some language files from the looks of it.

There is a list of things to do to debug at Debugging