Please help
This is showing up all of a sudden:
Warning [2] preg_replace() [function.preg-replace]: Compilation failed: lookbehind assertion is not fixed length at offset 8 - Line: 406 - File: inc/class_parser.php PHP 5.2.12 (Linux)
using mybb version 1.4.4
Why on Earth are you using 1.4.4?! It was released well over a year ago, there have been many hundreds of fixed bugs and some very serious security issues patched since then. It's a miracle you have not been hacked. This bug was fixed months and months ago, you wouldn't be having it if you were on 1.4.11. It always makes sense to be on the latest version when asking for support, your issue may have been fixed, like this one has been, running a version this old is just crazy. You're 7 versions behind.
[Wiki: Upgrading] (Broken link, head over to docs.mybb.com instead)
Did you not see the warning in the ACP telling you to check your version for the past year??
Ok I upgraded, but I did have one file that did not overwrite the current file on the server
when I ftp(d) the new files:
inc/languages/english/admin/tools_warninglog.lang.php
Is that a problem?( everything seems to be working ok)
Upload it again if it didn't overwrite properly, may not have been changed between 1.4.4 and 1.4.11 but I'd upload it again to make sure.