old 5.4 site adding [base_url]/customUrl%% to all links

Permalink
I know 5.4 is a very old version but I can't upgrade this site. Anywhere there is a content block with a link in it, it's adding "[base_url]/customUrl%%" to the links and a bunch of %'s to the end.

Has anyone encountered this? If so, how did u fix it?

I would be ok with an htaccess fix. Here is how my url's look...
https://www.mysite.com/about_us/customUrl%%http://www.targetsite.com...

What I need...
http://www.targetsite.com

No matter what I try I cannot get it to remove those parts....any help??