I am having a issue that seems unresolvable running Windows 10 under Parallels Pro Edition on a Mac with Sierra installed. When I boot, I get a screen with the Windows twirling dots that say "Administrator" and, under that, "Welcome". This persists for 5 to 8 minutes while the machine does various things--accesses disks, the interent and so on. Eventually, I get a screen that says "Invalid handle" and a box to enter a password. There is no password as I set up the VM to run without needing one and, indeed, if I then just click on the adjacent arrow the machine will go on to boot. The problem, of course, is that this entire rocess can take 10 minutes. I spent 1.5 hours the other day with Parallels Support leaving my system in a confused state and the issue unresolved. They finally said I should call Apple for an ACL reset, which I did, but it turns out under Sierra there is no such thing. Sierra apparently repairs permissions automatically and on the fly and gives users no way to do it manually. Looking at Windows online discussions this seems to have been an issue for some people in the past: https://sysoperators.blogspot.com/2016/02/windows-10-handle-is-invalid-at-logon.html . But that was using different emulation software (Citrix) and some time ago (February) as far as Windows updates go--I did not have the problm until I updated (a) Windows, (b) Parallels and © the MacOS. I doubt it applies today and am reluctant to try what that link suggests now since my machine in its current state does eventually boot and become usable. Does anybody else have this problem? Has anybody found a fix?