An "Unable to cast object of type" error can occur with certain directory settings

When certain directory settings are used, an "Unable to cast object of type" error can occur.

Steps to reproduce:

1. Start with a clean RomVault instance

2. Place the Mamma MIA DatVault DATs into your DATRoot using Master Directories and Subdirectories

3. Change the directory settings of the RomRoot as shown in screenshot #2

4. Apply settings

5. Close the window so the DATs are reprocessed

6. An error will occur

Expected behavior:

• RomVault should not throw a crash-like error

• If the directory settings are incompatible then a friendly error should display

(screenshot 1, 2)