I had the same error message while trying to program the Btech UV-5001. Once I put the radio in VFO mode, I turned it off and back on again. I was able to read and program the radio. I have no idea why this worked, but it did. Good luck.
From: Jeff Hughes <jeffreyhughes@earthlink.net> To: chirp_users@intrepid.danplanet.com Sent: Tuesday, October 18, 2016 9:59 AM Subject: [chirp_users] "Error Reading Data from Radio..."
Trying to download radio image fails with the following error:
“An error has occurred
Error reading data from radio: not the amount of data we want”
Radio is a BTECH UV-5X3. Using latest Chirp build (downloaded this morning). Running on Mac, 10.10.5 (Yosemite). Python runtime is installed. I don’t see anything relevant in the FAQ or in recent threads on the list. I tried resetting the radio to its defaults - no change, same error.