some days ago I noticed that it was not possible anymore to comment posts on three WordPress sites I run. Comment for pages still did work.
I looked deep into it and found out that as soon as I disable Akismet commenting posts is working again.
The bad thing now is that a lot of spam is getting through and treaded as ham, although I have two other antispam plugins still active (Antispam Bee and NoSpamNX). So I really would like to get Akismet back up and running again.
I tried to check since when this issue accured but cannot tell you. Spam comments are deleted here after a month. And during this period not one spam was caught for comments on posts. So the issue is here for a while now.
The only thing the three WordPress sites have in common is that they all are using a pretty old theme. Did more than less recently something change which I have to put into the post or comment templates?
I'm happy to provide more input if needed. I really would like to solve this to get Akismet up and running again.