If you delete all of the placeholder virtual machines from a datastore, unmount the datastore, and remount the datastore, recreation of the placeholder virtual machines might fail.
Recreating the placeholders too rapidly after unmounting the datastore can fail with the error NoCompatibleHostFound.
The associations between ESXi hosts and datastores are updated at 10-minute intervals. If you recreate the placeholders after unmounting and remounting the datastore but before the next update, the host cannot be found.
Wait for more than 10 minutes after unmounting and remounting the datastore before you recreate the placeholder virtual machines.