Cache can become corrupt with "Unknown Tree settings in DisplayTree" error

The cache can become corrupt if Dats are rearranged and updated in a certain way.

This issue was reproducible by one user by doing the following:

1. Place two copies of the same DAT into your DatRoot like this:

   1. /Testing/dat1.xml

   2. /dat1.xml

2. Ensure the directory rule applied to both DATs has "Don't auto add DAT directories" disabled

3. Update DATs

4. Add an additional copy of dat1 into the main directory so you now have three copies of the DAT like this:

   1. /Testing/dat1.xml

   2. /dat1.xml

   3. /dat2.xml

5. Update DATs

6. RomVault will trigger errors upon DAT update

Note that this issue only occurs when doing a normal DAT update. If refreshing all DATs after step #4 then the normal dat merge conflict error occurs.

(screenshot)