Visitor Group can't be opened in FF

Description

The bug only happens in FireFox. It has been reproduced in 10.0 and 10.5.

Steps to reproduce.

1. In the Chrome browser, create a visitor group with at least 6 criteria options of Geography Location. Set any values for Continent, Country, City and save it.
2. Open FireFox
3. Go to the created visitor group.

Expected:
VG should be able to open correctly in FF.

Actual:
The VG screen displays an error window "An unhandled error has occurred in a background request."