Please try to close NavStation and do the following:

1. Open File Explorer

2. In the address bar type %APPDATA%\NAVTOR\NAVSTATION-4

3. Find the "adp" folder and delete it.

4. When starting NavStation again you will see "Optimizing databases" message in the top right corner while the adp folder is automatically regenerated. Please wait for these messages to disappear and then try to access the ADP data again.