I beleive I found the culprit.
Under Preferences > Preference Options > Show confirmation pages for posts
I believe you have that enabled which is why you are getting that screen. If you uncheck it, it should not take you to that extra page.
Let me know if it fixes it.
Yes, it appears to be working for me now. While this is on the newest page of the thread, I was able to click the previous page and see it and then click Next and get back without any error messages.