Hi,
I have been able to replicate your "issue" (see attached image) and there is nothing to worry about it. It is actually a non-issue.
When you select import, LR will chose by default the path used the last time which is stored both in the catalog and in the preferences file.
- If there is an entry in the catalog, then it uses it regardless of the entry in the preferences file
- If there is not an entry in the catalog, then it will use the entry in the preferences file
- If there is not an entry neither in the catalog nor the preferences file, LR gives you that message
The good news is that after if you accept the message, go to the import dialog and perform an import, both entries (Catalog + Preferences file) are updated and you should not receive the message again.
Note:
I have experienced unexpected changes in the preferences file after upgrade, so it would not surprise if this indeed was an unintended issue when you performed the upgrade.
Additional info about the location of the entries in the catalog and preferences file:
Preferences
File in windows 7 64 bits:
C:\Users\<username>\AppData\Roaming\Adobe\Lightroom\Preferences\Lightroom 6 Preferences.AGPREFS (it is a regular text file)
Catalog:
Table: Adobe_VariablesTable
Variables:
- AgImportDialog_destinationFolderPath
- AgImport_importDestinationFolderPath