Undefined pop up error in Moodle
Moodle and TCOnline don’t play well together when you have tabs open for both at the same time. We are still investigating but here is what we can share.
The issue presents itself in a few different ways
- You may get a small pop up window that just says “undefined”.
- You may see an error saying “request headers too large”.
- You may see nothing unusual but a page just doesn’t load completely or doesn’t seem to work properly.
- It occurs most often with Quickmail and the participants list in Moodle but it can happen on any page.
What is the cause?
- It appears to be caused when a user has TCOnline tabs/windows open in the browser at the same time as Moodle. The problem is caused by the TCOnline cookie.
- It isn’t consistent, sometimes you can have TCOnline tabs and Moodle open without encountering any problems.
What is the solution?
- Sometimes just closing the pop up and/or refreshing the page is sufficient.
- Closing the browser (not just the tabs) and reopening it seems to clear resolve it.
- Just closing the TCOnline tabs may help but not always.
- Using a private window for one of them or a different browser for each will also avoid the issue.
