Great and working

This is great plugin! I use PHP and JS on my site, works stable.
However, minute ago i’ve faced an error and i cannot change my PHP. Could you recommend me a way to rescue my code, because i need to alter it..

Basically, my code ends, but browser does not detects the ending tag, and the result is – anything after textarea, including save button is smashed.

ps. before the update to latest wordpress this code was fine.