i've previously replied just above yours, saying how to duplicate the php8 issue, and how to fix the cookie issue.
https://www.ubbcentral.com/forums/u...-upgrade-to-version-8-0-fails#Post266332the corrupted cookie issue is corrected and the fix should be out in a version update shortly. its already live, in testing here on ubbcentral.
the error is that the array stored in the cookie never gets desanitized when retrieved, but the array gets sanitized when storing in to the cookie. so it gets corrupted -- redundant sanitizations on the manual new user approval page. php5 and php7 were not picky about strings and arrays, and ignore the attempt to create an array based on the corrupted cookie data. php8 is strict and will throw an error when an array is expected but not given. i have no clue how long this bug was in the code, but its probably been there for over a decade, which is well before my time developing for UBB.threads. consider the bug to fixed with the release of UBB.threads 8.0.1
as a side note: the cookie information your are sharing to the world in your posts, are your forum newuser stats for the past 24hrs, 1w, 1m, and admin and referrer log counts at the unixtime stamp listed. if you dont want that information shared to everyone, edit your post.
