I'm sorry, I don't have a solution for you, only a "me too" post... but with a slightly different error. Updating macOS on Big Sur isn't working for me either. james@Jamess-Mac ~ % softwareupdate -i "macOS Big Sur Beta 9-20A5384c" Software Update Tool Finding available software 2020-10-01 09:28:22.990 softwareupdate[3891:516909] Creating client/daemon connection: FC1D1CA5-E086-474D-A4A9-4BE8EF30AC61 Downloading macOS Big Sur Beta 9 downloading: 100.00% Failed to download & prepare update: Error Domain=SUMacControllerError Code=7721 "[SUMacControllerErrorPreflightWakeupFailed=7721] Failed to perform PreflightWakeup operation: [MobileSoftwareUpdateErrorDomain(MSU):MSU_ERR_INTERNAL_ERROR(7)]" UserInfo={NSUnderlyingError=0x149606b30 {Error Domain=MobileSoftwareUpdateErrorDomain Code=7 "No service connection" UserInfo={NSLocalizedDescription=No service connection}}, SUMacControllerErrorIndicationsMask=0, NSDebugDescription=[SUMacControllerErrorPreflightWakeupFailed=7721] Failed to perform PreflightWakeup operation: [MobileSoftwareUpdateErrorDomain(MSU):MSU_ERR_INTERNAL_ERROR(7)], NSLocalizedDescription=Failed to launch the software update installer. Please try again.} I noticed that the beta profile was not installed at first so I installed it and then the latest beta (beta 9, at time of writing) showed up in Software Update, but I can't install it.

@Ben, I didn't see your reply before posting my own... the /universal/ was what I was missing -- I'll give it a try, thanks!

Getting the same issue with Xcode 14 beta 2. The same view works in SwiftUI Previews without any problems in Xcode 13.