metatag breaks website

Without any further explanation, it is impossible to understand what your problem is.

Which errors did you get (watchdog?)?
Did you install a previous version (which?) of this module afterwards, and then it works again, or just uninstalled the module?

@Stealth: Can you also please mention what sort of page you see the problem on, e.g. a Views page, a taxonomy term page managed by Panels, a node, etc? There's documentation available if your site is hitting a White Screen Of Death with instructions on how to identify the errors that your site might be otherwise hiding. I really do want to ensure I / we can fix all problems in the module, but I need a little more detail in order to identify what's going on. Thanks.

*looks around*

*scratches head idly*

Tadaa!

:-D

Some of the theme functions changed recently, so maybe it just needed the caches cleared or something? Anyway, I'm glad it's working now.