Finally the issue appears to have been accepted and passed on to the correct team. Hopefully a fix will come out before too long. By the way I'm not sure that it really is a permissions issue but believe it instead to be a flaw due to some change made in the Parallels (prl_fs.sys) file system driver which causes CreateFile to fail where it used to succeed. The actual error code may indeed be ERROR_ACCESS_DENIED but that is more or less irrelevant as it isn't the true cause. Issues in other programs may also appear to hint at it being a permissions issue such as with Visual Studio when not running as admin and attempting to open a solution on a Parallels share. Unexpected API failures tend to lead to unexpected behaviour and this can be very misleading.