I updated from v1.3.2 to v1.4 this morning. In File Manager I can see the unencrypted drive (U:), folders and files but they are not visible to SyncBack.
I have been using SyncBack to backup files onto U: for several months without problem. After doing a system restore to get back to v1.3.2, SyncBack works again.
Before doing the restore, I tried unmounting and mounting again, and rebooting my machine but that did not fix the problem.