I have a minor problem with Handbrake and I am hoping that someone can help me. I transfer all my DVDs to ISO using Clone DVD then mount them using VCD so handbrake can rip to MKV. Every so often I get an ISO that Handbrake will not open. An example is the box set of Grimm, 6 disks. All are queued except disk 1 which will not even try and load. Any suggestions.