Critical error within theme editor

Hi, I’m also experiencing a critical error with the Patistry theme but only on the theme editor section. I’ve deactivated and reactivated plugins in turn but there’s no resolution. Site still working but unable to to edit things in the theme editor. I’ve used theme editor to make the change in code i require but this also hasn’t worked, are you able to have a look and hopefully override the glitch. I wish to change the background colour from #b9cd32 to #f09894 is all.

I look forward to hearing back from you and I’m happy to assist in anyway I can do to facilitate your help. I can send video to your email for example.