[SOLVED] – ARD crashed immediately after upgraded to v3.9.8 (Sonoma, Sequoia)

Like others, I recently had problems with Apple Remote Desktop after an update. An ARD update to v3.9.8 (App Store) was performed on Sonoma macOS v14.7. From that moment on, ARD crashed immediately after it was opened. The "Remote Desktop" window was briefly displayed, disappeared again and I received the crash report. ARD, on the other hand, worked perfectly under an alternative user account. Thus, the problem was to be searched on the original user side.

I tried all the measures I could find, and also my own methods (safe mode, root user, deletion of various user-dependent files - even in /private/var/db). Nothing helped.

- Excursus begin -

By the way, it should be pointed out here that it is not necessary, as I have read in other postings, to restart the Mac to activate a restored preset file (com.apple.RemoteDesktop.plist). It is true that it is not sufficient to just stop and restart ARD, since the default settings are cached and thus remain intact. After termination of ARD, the user's own process "cfprefsd" in Activity Monitor must be terminated ("Force quit" is NOT necessary). The process restarts immediately under a new process ID. Only then will the presets be read out of the Plist file as soon as ARD is restarted. 

- Excursus end -

Even an update of macOS to v15.3.1 Sequoia did not help. What helped ARD come back to life was a downgrade to the previous version v3.9.7 (luckily I still had it in the Time Machine Backup). This ARD version played well with the (defective?) preferences settings and I could export my lists, then upgrade to the current ARD version, throw all presets overboard, start from the beginning and imported the lists incl. all the passwords for the clients. Ugh.

Since then, the new version has been running stable again. I still wonder what went wrong. I will now renew the exported lists from time to time and keep them well. They saved me even more trouble.