felix ulrich

I had a similar issue with Nginx when trying to get HTTP Authorization headers to work. Nginx uses directives not htaccess however. 

You might try using this:

https://www.litespeedtech.com/support/forum/threads/ipb-htaccess-furls-and-litespeed-cache.5430/

Litespeed has relatively good support also, assuming you're using their paid webserver, but the free one is relatively similar. You can try using the suggestion in that thread I mentioned or open a ticket there with them. Someone here who is better with htaccess and rewrite rules may have a better answer for you than me - but I've found that having some support goes a long way for these things. Maybe consider paying for plesk. The support's next to none and for $10/m you'll get lots of it when you have issues like this that are more related to the configuration of your webserver/stack than related to IPB itself.

I apologize, you can download the theme and edit XML then reupload it as a newer copy. However this didn't fix the issue for me.

What did work was:

1) In the admincp, go to the theme menu, select edit html/css  next to the theme
2) In the search field search for "theme by"
3) In the results in the navigation menu, select footer, and to the right you'll see the "Theme by" in the code. Either remove it or replace it.