Viscosity version 1.9.2 is now available for macOS! This is a small update designed to address a single issue related to system updates on macOS 11 (Big Sur). Version 1.9.1 remains the latest Windows version.
We've identified a situation where Viscosity could inadvertently trigger a bug in the macOS update process when updating macOS 11 from version 11.0 or 11.1 to version 11.2.x. This bug can result in the update process stalling at a black screen (with an Apple logo and progress bar) for affected installs.
While this appears to be a bug in the macOS update process, and not directly with Viscosity itself, as it is highly disruptive to those impacted we've elected to push out this update with a workaround in Viscosity to avoid it. If you're running macOS 11 and haven't yet updated it to the latest version, we strongly encourage you to update Viscosity to version 1.9.2 before proceeding.
It's only possible for this bug to be triggered in a small number of instances, and so the vast majority of Viscosity users will not be impacted. Users not updating between the above versions of macOS shouldn't be affected. Users connecting TUN connections are not affected. Users connecting TAP connections may be affected depending on the VPN configuration and cached network settings.
If you've already tried updating macOS 11 and the update has stalled, you can boot your computer into Safe Mode (please note that the process differs between Intel and Apple Silicon Macs) and re-run the update from there. It may be necessary to download and run the full macOS 11 installer from the App Store to complete the update. It is not necessary to erase your computer or restore from Time Machine. If you're unable to boot your computer into Safe Mode, then the cause for the stalled update is unlikely to be related to Viscosity.
Special thanks to Tobias Punke for initially reporting this issue.
Version 1.9.2 Mac Release Notes: