Yeah I'm getting the same errors with some of my agents. They add an internal note, and after submitting the note, the popup screen goes blank (all white). If I close the popup and refresh the main page, the note is sometimes added, and sometimes not.
I have restored from a previous backup of 2.4.9 if that matters....
OTRS: 3.0.9 & ITSM 3.0.4 - OS: Windows 7 - DB: MySQL - Heaps of random/useful hacks
[Major Code Changes]
Ability to search ArticleFreeText