Need help please!

Um...What does this error mean "Invalid URL (http:///show_msgs.php?topic_id=26502396&union_id=13361). URL must start with either http:// or https://"?

Nevermind. I figured it out.

Looks like it's cut out the start of the url (e.g. gamespot.com), leaving the trailing slash of the address, which is confusing it, as HTTP and HTTPS web addresses only have two slashes after the protocol identifier (instead of the three that it's left there).

Basically, it doesn't think it's a proper web address, and it's alerting you to that fact.

I'm assuming that you're trying to link an address, so you'll just have to try putting the address in again, possibly typing it all out manually just in-case.

Edit: Well at least you've fixed it yourself now :P.