Huh?
I Have error logs turned on in the control panel of ubb. Even just tested for logs it works.
Also checked in the site control panel for errors.

Okay finally found it.
Same error as you posted.

For my info what creates the file never seen it before? But then I am new to apache.

For now I just commented out the new portion.
just below:

and before


And it works again.

I see exactly the same symptoms and the same error in the error_log file.

Looks like not everyone has this function available, so going to have to alter this a bit so it doesn't request the headers when the function isn't available. Will have this fixed for the final release.