Unsuspicious Wrote: If people actually read the error, they'd see that it's something to do with eval(); Which indicates the templating system.
In your previous thread, you said it only happened for staff on the showthread pages, my guess is that you used the PHP in templates (template conditionals) plugin to give yourself some fancy thing in the postbit, which is broken.
The codes were not wrapped properly in functions_post -- but it was more than what was stated in the error.
I have fixed these in the above code for him from my previous reply. It should work - however a different error might occur as this file looks like it was modified more than the eval(); that was incorrect.
P.S. Thank you for as well realizing no one knows how to read.