Software Update: When clicking on "update now," and after authentication my username, I get a consistent "download failed" message. "An error occurred while downloading the selected updates. Please check your internet connection and try again." (I've triple checked that I'm plugged into the functioning ethernet, and WiFi)
I've tried to get around this by directly downloading the "Install macOS Big Sur Beta" directly from the website. (https://developer.apple.com/download/) I'm able to install the Developer Beta Access Utility successfully, and have managed to then download the installer (Install macOS Big Sur Beta), but when I try to open the file I get an error message, "This copy of the Install macOS Big Sur Beta application is damaged, and can't be used to install macOS." I've tried redownloading/restarting/etc multiple times without success.
Using another computer (running Catalina) I managed to create an bootable USB drive, but I confess I'm not certain how to boot from this drive when restarting the DTK as things are different than before.
Best,
Tpetdoctor