1. Open library with existing group from old JabRef version
2. Select group
3. Edit group color
   
4. Dialog "Change of Grouping Method" appears.
   
5. Click "OK"
6. Group is unselected --> maintable changes
7. Click on group
8. Correct number of entries is displayed, group color not shown
   

In another experiment, only 1/3 of the entries got the group color

Questions:

• Why is the dialog "Change of Grouping Method" appearing?
• Why are not all (or none) entries marked with a color?