Hi,
Not all file formats are supported for tagging. In your case you are using MKV container format that have very very complex tagging format and in our tests for most cases adding even a single Character to tags can result in remuxing whole file and can take several minutes per tag change.

If you have found any application that can accurately, stable and quickly tag MKV file pleas give us example and e ill check it out to see hat engine it uses.

NOTE: MM uses official MKV/Matroska libraries and tagging is one of least documented things along suggestion that metadata tag is preferred to be saved on encoding the file.

Hi all,
Basically I moved a load of .mkv files to an external hard drive using the in library move function (right click and copy to destination)
I went for copying because I was concerned that some of the meta-data might be lost, and indeed it was - as far as I can tell it's just the stuff that isn't stored as part of the file, so things like actors that MediaMonkey has additionally. It has mostly only affected .mkv files, all of which are affected, although a handful of .mp4 files have also been affected. .avi files are unaffected.
I would like to know how to move or copy them and get MediaMonkey to also copy the other fields of meta-data: actors, producers, dates etc. Ratings have also been lost which kind of surprises me.

Thanks in advance