I always use the same procedure when relinking doesn’t work.
– where is the source file from? I’m guessing footage that doesn’t relink is often material created in adobe media encoder?
-what information does Avid have to try to do the relink? Tape or Tape ID column info? Timecode info? File name info? Avid doesn’t typically care if the files have been renamed inside Avids bins, as long as the metadata for the files is complete. This again usually comes down to the transcode process.
If the computer can’t do the relink, ask yourself what it is or is not seeing that is confusing it.
Often this comes down to timecode or clip name confusion/repetition.
In response to your mismatched Avid versions, it depends how mismatched they are. Avid has done a lot of changes in the last couple of years. I would be hesitant to mix a current version with a version from 2013, although it wouldn’t surprise me that the actual sequence opens. If you are doing no live linking for the edits, i would be less worried however about a version that is a couple of years out of date. Other functions in the timeline may not work however.
You mentioned multicam in your original post. Are you always committing multicam edits before trying to relink? Not doing this will certainly cause a clip to not relink.
In my experience, if the media is transcoded properly outside of Avid, or when possible, inside Avid, there are rarely relink issues.
MP4 sources, with the same starting timecodes and pesky names that are constantly repeating would be the first thing I would address before transcoding. (items that are named clip001 with a 0:00:00:00 timecode never make it into my system) They are renamed according to shoot date, and if necessary camera model, and shoot time of day timecode is added to the files through an external program. I find this issue to be one of the main reasons people have trouble relinking media, or having the wrong clip relinked.
I find very few file types won’t come into Avid anymore, but i do typically do my transcodes in Resolve because of the speed. Again, making sure timecode and tape name metadata is set up correctly.
If it was as common as a problem for me as you seem to be having, i would probably start charting which files are not relinking, and start tracing back their origin, and perhaps their use in the timeline.
It is true, I will get a clip or 2 that for what ever reason just won’t relink, and it is way faster to simply manually edit that shot back into the timeline, but I find those cases to be quite rare.