A bit of history on my troubles in case it's relevant to the problem: V87 on both minis - Fixed by replacing a splitter that was originally installed by DirecTV. I have Frontier FiOS (originally Verizon FiOS). V58 on Both Minis - Fixed by replacing the CableCard and talking to Frontier FiOS via chat support and had them pair it to my Bolt+. Both errors, fixed. In the process, I'd also replaced my Verizon MI424WR rev. I with a Verizon FIOS Gateway FIOS-G1100. With the old router, I had to open up ports. With the new router, I did not. Both Minis worked just fine for almost two weeks as I detailed in the next paragraph, without forwarding any ports. I then reset one of my Minis, as both still had information on my old Bolt device (which I replaced with a Bolt+). So, Mini-1, I had up and running for at least a good month. I reset Mini-2 a bout two weeks ago and had it up and running just fine. Just over a week and a half later, Mini-1 started popping up with C421 errors on the channel guide and C422 errors on My Shows. The person using the Mini did not tell me until Saturday afternoon, and it's now just past 3:30 am and I just got a message on my TiVo Bolt+ that there was an update. I have not tested Mini-2, yet. In short: I'm getting C421 and C422 errors on my TiVo Minis. Any ideas on how to fix this?