I moved this to its own forum thread because there is no mention of sf_name in your issue report.
Failed to open directory “sf_name”. Error opening directory ‘/media/sf_name’: Permission denied might be related or might be different.
For some reason, file permissions are no longer already prepared by vm-config-dist This might be a usablity bug, that will be investigated later and will likely be fixed in version 17.4.0.7 and above. (Unreleased at time of writing.)
But there is no need to wait for a fix. Users might be able to easily fix this.
Try this:
Shared Folder Permission Fix
(written just now)