Now, in the middle of a series of small projects, I bumped into this anoying thing of the "random" thumbnails shown in the media room after 2-3 projects, that (which is consequent again) are also copied in the timeline when the media file is copied. The thumbnails do not represent the media that is behind it, and that is very confusing and anying.
I can of course repeatedly empty the folders mentioned before in this topic (which does not always help), or save the project, close PD16 and restart it again (which mostly helps). But I would recon that this "feature" should not happen, is very disturbing, and should be fixed in one of the next updates!
I really hope that the PD developers are reading this forum from time to time. In the next release reliability, stability and speed are foremost needed.
Thanks!