@Engineer I am running into this same Springboard crash when posting a Critical Alert notification in the iOS 26 Simulator. @mnydigital Did you ever get a resolution, or even a workaround, to this issue?

Update. I was wrong. The version included in Addtional Tools for Xcode 11.4 does appear to work on Big Sur. The question is will it continue to work in the future? Also, why are these tools still listed on the main Bluetooth developer page if they are no longer supported?