Will developing my Many Tremendous Troops asset, I've noticed that the images of the enemies whose filenames start with a lowercase letter will sometimes disappear from the Resources and/or the Enemies database. The images are still in the img\enemies folder but there is no reference to them somewhere, so their image does not show up in the Enemies database. This happens for the last 6 or 7 monsters in the database.

I haven't noticed it with just the Enemies database but it might be something you want to keep an eye on.