Recently I got an error message after trying to do provision to the Desktop app.
I tried to Reinstall the app and then provision but still the same error .
Thanks for the advice.
Also if the 3cx system is on update 5 make sure you download the desktop app again from the webclient, uninstall the current version and install the one downloaded from update 5. If installing an older version with update 5 you will receive this error.
I have the same issue, had to revert users that were running the desktop App to the old version (small) version that's no longer supported or developed but still works.