Users cannot reply to topics/PMs

[The Honor Empire]

I submitted this to support, but I wanted to see if anyone else had this issue and if there is a quick way to resolve it?

No standard users can submit a reply to a topic or submit a reply to a PM. When they click submit, the button will say saving data then immediately go back to the submit button. However, no data is submitted. This appears to be impacting non-admin members. Admins can reply, but non-admins cannot (e.g. users in the standard "members" group). I used the support tool to disable all plugins and applications and it still did not work. I also used the IPS Support theme and it failed. I tried in multiple browsers as well. This used to work, but something in the last update has changed.

Any ideas?

Thanks

[chilihead]

PHP may be out of date.

[Lord Balandar]

Running: PHP 5.5.32 (cli) (built: Feb 26 2016 15:10:44)

The replies work on my test forum, running on the same host, but not in the production environment. 

[Lord Balandar]

Solved. The update process failed to update some files. After manually uploading, users can now submit replies to topics and PMs.