I'm using VMware Workstation Pro 15.5.1 with monolithic disk files (on a Win 10 host). I worked with snapshots, but always deleted them again because they're not needed anymore.
Unfortunately, it does not delete the Snapshot files from my disk, when I try to delete them by hand it says This file is required to power on this virtual machine. If this file was moved, specify the new location.
*.vmdk file which works independently from the snapshot files.
Solution:
1. Shut down the virtual machine
2. Go to the option 'VM' > Snapshot Manager
3. Select each snapshot and delete them from left-to-right
