I am having the same issue as Kyla, b/c I know I use to be able to reference Giphy, etc w/o any issues before. And I think it's connected to my sigs as well. It seems like if it isn't a .jpg (or the like) the forums doesn't support it?
This is more of a note, and I did message you initially via Facebook about it.
Every time, EVERY TIME, I need to clear the cache/cookies/the boogieman/whatever off of my internet browser, I run into issues logging into the site, but usually b/c I mistyped the password and I get in on the 2nd...