Jaks posted on Aug 12, 2016 4:33:09 AM - Report post
@Neo - Tested again and got both the 404 error and the missing text in the Compose window after Preview - Go Back when doing a PM. So I disabled Addblock Plus as suggested at the bottom of the 404 Error message and Voila.
Tried a couple more and had neither problem. Addblock Plus seems to have been causing my problems.
Unfortunately, now I don't have anymore weird problems to whine about. Not much fun in that.