"HK Download" error - MakeMKV needs internet access to download keys. It is enabled by default. Check internet or confirm setting in MakeMKV allows Internet access. I *think* some downloads are from Russia(?) - make sure your FW/router is not blocking Regional IP addresses.
Download failure is not related to the SCSI error messages - those are still power related.
Desktop does not necessarily equal better power.
Use a "Y" cable w/2 x USB port connections, AC adapter (if chassis supports it), or a good, high amp output USB hub.