same here, noticed on Win10x64 Home and Win7x64 Home (local profiles)
I guess it has something to do with the locking of the ntuser.dat hives,
In some cases it seems ntuser.dat is locked too early, so it can not be accessed when logging in
this happens especially when a user logs into the machine which normally doesn't, and then the "daily default user" tries to re-login again (but not in every case, a bit confusing)
booting into safe mode and rebooting again fixes the problem once