A Thread Post Error

Why is it that when I attempt to put any threads that have things such as links, that when I submit; it says "Unable to contact server".

But when I try again, the reCapcha re-opens and it still says the error below the thread.

For a fact, I know it isn't my internet. My internet is good and I even sat next to the router to ensure it isn't my internet.

Does anyone know a fix?

EDIT: Saying this, if I don't actually change the words to a link and just paste it on the thread it could work for me

EDIT 2: Doing what I said in edit 1 worked, so uh. Okay.