acp/ is a special case. It’s not mentioned in the official Woltlab rewrite rules either, it doesn’t use pretty URL’s to work right. It does give a redirect loop now, it mentions the session has timed out.
Adding it to the regex doesn’t work, either.
For now, some things seem to work correctly:
- Regular pages work: https://staging.guildwarslegacy.com/guru-archive/
- Some dynamic content works: https://staging.guildwarslegacy.com/article/7-where-to-find-the-new-pve-elite-skills/
- The forum overview doesn’t work, it gives an error not found: https://staging.guildwarslegacy.com/forum/
- Strangely enough, some threads seem to work and others don’t: https://staging.guildwarslegacy.com/forum/thread/1409-lgit-legit-guild-lgit/?pageNo=6
→ The page navigation seems broken. - Other forum threads don’t open at all and give an error message:
https://staging.guildwarslegacy.com/forum/thread/2956-chat-filter-filter-out-gold-spammers/
→ When I go through the logs, this is the info that I find; Call to a member function getLink() on null. That points to it not recognizing the URL (it has gotten /forum/thread/2956-chat-filter-filter-out-gold-spammers/ passed through according to the log).
Main issue here seems to be that the ?pageNo=6 isn’t recognized 
I’m not so good with regexes… do you have any idea?