I just got the same error. My system had a panic while the Parallels session was just starting to open the disk.
When I tried to revert to a previous snapshot, I got a an error and the Error code was 419502468.
Then I tried to use the Parallels Explorer to look at the files, same issue, not able to open the image.
What practical use are snapshots, if you are unable to revert to a snapshot!