TypeError: Result of expression 'this.get()' [unde fined] is not an object
Has anyone had this or know why it would start to happen?
Nope, but I had a similar popup error this week and entered entered a support ticket with details. A few days later they released a hotfix. I would suggest you enter a ticket.
We're getting a similar error in our service desk since we did the 6.0.1 update (early last week). We're current on hotfixes (up to Tuesday of this week) and still experiencing this error.
We find that when this error is an issue we also cannot view or edit the contents of any "Text-Area" type fields, including Notes and Description. Clearing browser cache or CTRL-F5 is a temporary fix but my staff and I find ourselves doing this a half a dozen times a day (or more!). I have a ticket opened with support - they don't seem to believe me but I'm continuing to provide them with details so I'll let you know what I find.
You using IE7?