[@netweb Keymaster 12 years, 2 months ago]

A quick search of the interwebz reveals this:

https://stackoverflow.com/questions/21897786/what-does-the-error-php-fatal-error-cannot-call-overloaded-function-for-non-ob

It might not be explicitly a plugin based on that, maybe ask your web host provider about this one, it is pretty much beyond me.