I am also getting the Error – new_disprd failed with “Instrument Access Failed” pop-up when I attempt to calibrate. I am on MAC OS X 10.15.5 and I am using a Spyder4. I have tried USB ports on my laptop, on my connected keyboard, and on a hub (worrying about USB3 issues I have read about). I believe I went through the download process for Argyll when DisplayCAL launched, If there were additional steps (like manually expanding and installing) I didn’t understand how these proceeded and they were not done. I see that manual install outside of the control of the app is needed on some platforms.
I am attaching the log after a run with debug set on (and hoping I did everything correctly to get you the needed data). Any thoughts towards getting this working would be appreciated.
I am not sure if there is an issue with the log file I submitted or there was some other snafu that prevented the normal quick response here. In any case, the problem now seems to be intermittent with the Spyder4 connected directly to the MacBook Pro. I have captured and installed profiles for both of my screens. Any further guidance on why this does not appear to be stable on my platform, or whether further logging would be useful, would still be appreciated.