Help with myBB 1.8

I signed out of my forum and now the webpage is blank and I mean fully blank.

This is the source of my page when signed out;



I'm logged into the ACP fine though?

I can't sign back into my forum account though, so it's forever blank.

Cleared cache etc, nothing.

Also disabled any plugins and I'm still at square 1.

Any help would be appreciated it?

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EDIT: It seems to be just a theme >.>