Thread:Extension talk:WPMW/Special:SpecialPages stops working with AuthWP and MW 1.20.3/reply

It seems to be working fine for me with 1.20.4 (haven't tried 1.20.3). Are you sure it's AuthWP causing this problem, and not another extension. Although I guess it's possible it's AuthWP, it seems far more likely that it's an extension that interacts with the SpecialPages functionality, which AuthWP doesn't.

You really need to look at your php error log to see why you're getting that blank screen, and what's causing it. If it still looks like AuthWP when you've got that info, please get the log to me and and see what I can do.