Celine,
I can’t read the error message 1, because screenshot picture is too small and the message is out of focus. The message in your email "e\....mp4” seems impossible. I would expect it to say “e:....mp4”. Is your data and media located on some network drive? Is you CLAN installed on "e:" drive?
I would like you to try something to figure out if the problem is with media file or CLAN or your computer configuration. Newer CLAN distributions include “examples” directory in “TalkBank\CLAN” directory. I would like to open fie "TalkBank\CLAN\examples\elan2chat\mytheory.cha” and play any bullet. If media does play, then the problem is with your own media file’s format or where it is located. I assume that your university computer is just a personal computer located at your university. Some universities install CLAN in location that users do not have access to. Is this how your CLAN is installed? If you have access to “"TalkBank\CLAN\work” directory”, then try copying your datafile and media file to "TalkBank\CLAN\work” directory and see if it plays from that new directory. If your media file still does not play, then the problem is with your media file’s format.
If media from file "TalkBank\CLAN\examples\elan2chat\mytheory.cha” does not play, then the problem is with CLAN being unable to located directory where the media file is located or your computer’s configuration. Does your Windows 10 system have the latest Microsoft update installed?