In the last couple releases (I'm currently on 24.0.56) over the air EPG loading seems to be broken, at least for US ATSC broadcasts. I have no trouble scanning for RF channels and watching them, but MC won't update the OTA guide data, anymore. I suspect this is related to the work being done on subtitle support. OTA guide loading runs, does not generate any error messages, but loads 0 data.
Why do I need this? It's because several times a year my local broadcasters change their subchannel assignments and fail to notify the various agencies that supply guide data. In my most recent case, my local NBC affiliate moved the Quest network from 8.4 to 8.3. For the last 2 weeks MC2XML has been downloading the wrong data for 8.3. As a result I can't schedule recordings based on program name. The correct data is available in the PSIP stream in the broadcast, but MC no longer seems able to read it.
This is not unique to one PC. I have observed this on 4 different MC24 boxes.