Edit Artist won't allow last unbroken URL to be a protected twitter

I just checked artist #80034's URLs and every single one of them was dead except the link to their twitter, which is protected. If I add a "-" prefix to each URL except the twitter, when I try to submit it goes to a blank page, and the edit never goes through. I have to remove the "-" from one or more links to get it to work.

I was able to delete the Twitter link. The one that may have been causing the issue is the Pawoo ID link, which is still unresolved from issue #3918. In the meantime, what I've been doing, and what I did, was to mangle the domain to be "pawoo-net" instead, that way Danbooru doesn't trip up over it. When/If issue #3918 ever gets fixed, those links can always be fixed.