Welcome to the club. I posted this on URC's installer site. Haven't heard from any higher ups yet, but this was my original post:

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At least once a day I receive one of the following errors or problems

When uploading it will stop at:
11% 19% 31% 52%

Occasionally, at 5% or 11%, I'll get:
Upload Error: Invalid Answer - LimitedProgramLoadToPC [DLTR-2]

When downloading, I'll get these:
At 25%,
Error: Unknown protocol. [DLTR-4]
then this appears:
Remote Control not found.

Sometimes this will just pop up randomly when attempting a download:
Error code: 110-17UU-0001
Either the com port setting is incorrect, or the cable is defective.

I've uninstalled/reinstalled the software multiple times. Same problems. Happens in the MX800, MX850, and B&K SR10.1 editors. It's mostly the uploading that gives me the most headaches. I will have to try and upload the remote about 10 or 12 times before it uploads 100%. It will get to 11% or 31%, etc, as stated above, and just stops. I have to cancel out, and try again. Sometimes that won't work and I have to close and reopen the editor. Sometimes even that won't work and I have to reboot the computer before it uploads 100%.
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I don't use any USB-serial adapter. I use the com port on my laptop.