Encountered while trying to start VM created from System Center Data Protection Manager 2012 R2, using a preview VHD downloaded from microsoft evaulation center.
Error message it provides refers to not being able to write to the file, it being read only.
Troubleshooting: I tried changing file permissions locally, no effect!
Uninstalled Virtual Box, which was installed with local account having admin privileges. Re-installed it using “Run as Administrator” and tried to recreate the VM with same VHD. It worked beautifullly.