Could you please provide me with the replicating steps, like what were you doing when this happened? Does this happen with all the muse files?
Also, please send us the .muse file and the image that you were trying to add to firstname.lastname@example.org and mention this forum link in the subject.
I got the same dialog when trying to place (Command D) a 17 KB image. I was able to place this image in the past (about six months ago) on another page, and I was able to copy the image from that page and paste it on the page where the crash repeatedly occurred when doing a Command D with this image. When I tried to place (Command D) another image on that page, there was no problem.
The image is in the site folder. It is listed twice in Assets - there is no Red mark beside either of the images. There is a red octogon shaped symbol with a ? for another image, but that hasn't caused a problem (unless that is somehow related to the image in question).
Could you please share your .muse file with us to investigate? Please email it to email@example.com. If your file is greater than 20mb you can use something like Adobe SendNow or SendThisFile.
Please do not forget to mention link to this forum and the Image name which you are trying to copy over so that we can investigate the issue.