DCP-o-matic crashes when attempting to import content if the last-used directory was a network share that is no longer accessible.

Expected Behavior:
DCP-o-matic should handle the missing network path gracefully and allow the user to select a new import location.

Actual Behavior:
When attempting to import content, DCP-o-matic tries to access the unavailable network path saved from the last session and crashes. This prevents the creation of a new DCP from local files.

Additional Context:
This issue makes it impossible to proceed unless the network share is reconnected or the last-used path is manually reset, which is not user-friendly.