Calendar: cancelling a new meeting creation leaves strange message box on screen

[pgorod]

Steps to Reproduce

1. Go to Calendar module
2. Click on one of the days, this will pop-up a large window with many settings to create a new meeting appointment
3. Click cancel at the bottom of the pop-up
4. See a message box on screen, saying undefined, loading, please wait.

Note: if you look carefully, you'll see the message box appears before, and below, the large modal pop-up. So the required fix might be needed before launching the pop-up, not after canceling it.

Your Environment

• SuiteCRM Version used: I was able to reproduce this on 7.8.12, 7.9.11 and 7.10 RC, so it's propbably everywhere

It's low priority.