I'm seeing some weirdness with the Rename, Move, and Copy tool.
Last night I did a lot of file organization on my server at home. I was doing both of these tasks:
1. Moving longstanding files in my library from my main "M:" RAID drive over to an external "X:" drive (video files I didn't want to delete, but had already watched).
2. Reorganizing newly imported files from my M:\incoming\ folder to the proper locations using metadata to sort them.
I got a number of different, and seemingly random, "MC encountered errors when trying to tag the following files" errors (and the referenced files didn't move). If it had just happened once, I'd have assumed that some other process was using the files at the time, and so they were locked. However, this doesn't seem to be the case.
For one, running the exact same tool on the same files immediately after getting the error would usually "fix" it, for at least some of them. In one case, I had 15 files that failed to move (out of a batch of 50 or so). I ran it again on those 15 files, and then all but 3 of them "worked". Then, I ran it again on those three (immediately, without doing anything else) and they moved correctly.
When it happened the second or third time, I decided to investigate. I checked the permissions and read-only status of the files in question thoroughly. They were as normal as any of the other ones. Plus, after the first set of errors, I made sure all other processes on the system that might even possibly potentially be using the files were shut down (like the AirVideo server, for example, which sometimes causes this). There was literally nothing else running on the box when I got some of the later issues that might have had a lock on one of the referenced files.
Lastly, it seemed to happen in "hunks". For example, I did a big batch Move on many of my more recent TV Show recordings and downloads out of my M:\incoming\ folder. This included probably 10-15 different shows. On that batch, I got errors for 3 different (but not sequential) episodes of one particular show (Secret Diary of a Call Girl, in this case, which is a silly but fun BBC/Showtime show if you've never seen it).
These files, though, were recorded at different times. Two of them were in their own subfolders of the M:\incoming\ folder, and one was in the root of that folder. However, 6 more episodes of that same show, including many others directly located in M:\incoming\, worked just fine. I couldn't see any pattern to the problems, other than that when it happened, the files seemed to have a tag in MC in common.