I updated my Sailfish Application SDK to include the brand-new 220.127.116.11 build, no issues there. Then I noticed that it had dropped my aarch64 build target, so I restarted the maintenance tool, selected it, started the installation, and it errored out:
Preparing the installation... Downloading packages... Downloading archive "2021.02.11-1Sailfish_OS-18.104.22.168-Sailfish_SDK_Target-aarch64.tar.7z.sha1" for component SailfishOS-latest-aarch64 (22.214.171.124). Downloading archive "2021.02.11-1Sailfish_OS-126.96.36.199-Sailfish_SDK_Target-aarch64.tar.7z" for component SailfishOS-latest-aarch64 (188.8.131.52). Installing component SailfishOS-latest-aarch64 (184.108.40.206) Extracting "2021.02.11-1Sailfish_OS-220.127.116.11-Sailfish_SDK_Target-aarch64.tar.7z" The command needs to be used under Sailfish SDK workspace, which is currently configured as "/home/direc85/SFOS"
I started the maintenance tool from the .desktop file as usual, and it has worked quite reliably for me.