All of a sudden, for the past few days, I have been unable to edit or delete posts in my WPFORO forums, which had been working previously.

I turned on Wordpress debugging and get these errors in debug.log when I try to edit or delete:

[08-May-2017 16:42:29 UTC] PHP Notice: Undefined index: animate_cat_menu_bar in /home3/doylest3/public_html/wp-content/themes/atahualpa/js.php on line 79
[08-May-2017 16:42:36 UTC] PHP Notice: Undefined index: animate_cat_menu_bar in /home3/doylest3/public_html/wp-content/themes/atahualpa/js.php on line 79

I have tried deactivating other plugins but that does not correct the issue.

What versions are you using?
what happens if you switch to the twenty seventeen theme?

I'm running:
Wordpress 4.7.4
PHP 5.6
Atahualpa 3.7.23

I will try switching to twenty seventeen and see what happens when I get a chance this evening.

fyi: the url to the site is: www.doylestownphotoclub.org

Update: I tried both the twenty seventeen and twenty sixteen themes and everything worked

Please go to ATO->Export/Import Settings export your settings and attach them to a reply (paper clip icon)

Export attached.

Something Interesting:

I downloaded atahualpa 3.7.2.4 and put it in a new theme directory. From my live site, if I do a preview and go to the forums, the edit and delete work fine. If I make that copy of the theme active, then they no longer work. Conversely, if I do a live preview of my original theme, the functions work there.

This has me stumped.

did you disable ALL your plugins at the same time to see if you could then edit a post?