EDIT: Never mind, I think. I seem to have resolved my issues by reinstalling JRiver, rebooting the computer, rebooting the NAS, and clearing the NAS SMB cache. I will leave this here now in case anyone else runs up against this, but, for now, I don't think further review is required.
ORIGINAL POST: My installation has started to behave unusually, but I am not sure whether it is due to the download of the latest version or because I reorganized my collection's file structure and reimported all the music.
I originally had all of my music in four folders, but my collection has gotten so large that it takes my file manager a long time to open each of the directories when I want to copy new files into them, so I broke the files up into a total of about ten folders. As I moved the files from three of the old directories into new directories and renamed those three original directories, auto-import began to re-import the files from the new directories. (The fourth original directory remained unchanged.) This meant that many of the original albums now had newly imported files in the new directories *and* pointers to their original but no longer accurate file locations. Eventually, when the auto-import finished running, it had deleted the original entries, so I did not at that point encounter "file not found" errors from trying to access files that no longer were on the drive in their stated locations.
I was happy with how easy JRiver made it to restructure the folder hierarchy. The only data casualties were with DSD files, which lost the metadata I'd typed in previously, causing me to spend an evening re-entering the metadata.
Today, though, using the 64-bit version, I began to observe behavior that I'd never seen before. I copiied new files into one of the new directories and imported it successfully. If I then had to change metadata or import or paste album art, I got "errors in tagging" or "file not found" messages. Then, looking at the directories themselves, I found a number of files with 0 byte sizes and a corresponding file of proper size with "(1)" appended at the end of the file name. To get JRiver to recognize that particular song, i had to delete the 0 byte file and then delete the "(1)" at the end of the second file's name. Then, when I click on the file's name in JRiver to get the track to play, I get another "something wrong with playback, file not found" error. If I exit JRiver and start it, I can play that track after restart, but I get the same error when it advances to the next tune.
I have been using JRiver since about version 17 and don't believe I ever have had this behavior before. At least today, it's been persistent. However, with the recent changes in the library structure, I am not sure whether it's a bug in the new version or something that got screwy because I moved files around. Also, the cover art seems to be sticking only to a few of the tracks in an album. Any thoughts?