500 Internal Server Error on my Linksys wrt54gs2 after messing with ports

So last night I added some open ports so I could successfully play Fear 3 co-op. Well that went with success and I was able to play it. Today I'm trying to get back into my router settings but after I put in my username and password I get the "500 Internal Server Error".

Anyone know how to fix this?

 

I'd say you would need to reset the Router completely and set it back up from scratch.
And check for Firmware updates after you do it to make sure that's not a bug.