The first GM:
Problem 34501794
Sometimes (but not usually on my dev machine) the allow button generates no change in the System prefs.
The button stays available. The prompt text stays visible.
The kext stays unloadable.
In the System Logs the following messages appear:
Sep 15 13:39:19 MacHFS117 com.apple.preference.security.remoteservice[828]: objc[828]: Class AWDSecurityPrefAutoUnlockSetup is implemented in both /System/Library/PreferencePanes/Security.prefPane/Contents/XPCServices/com.apple.preference.security.remoteservice.xpc/Contents/MacOS/com.apple.preference.security.remoteservice (0x1001b68e0) and /System/Library/PreferencePanes/Security.prefPane/Contents/MacOS/Security (0x101db2900). One of the two will be used. Which one is undefined.
Sep 15 13:40:26 MacHFS117 com.apple.xpc.launchd[1] (com.apple.preference.security.remoteservice[828]): Service exited due to signal: Killed: 9 sent by com.apple.preference.security.re[828]
Rebooting doesn't clear up the problem.