At https://www.sparklabs.com/blog/viscosity-for-mac-version-1-9-2/ Sparklabs describes a bug with Viscosity for Mac. Viscosity is an OpenVPN Client.
A citation from Sparklabs's blog: "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."
A citation from Sparklabs's blog: "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."
