oh my god, what a buggy software...
after 3 hours try & error i finally found a solution...
(I carried out the steps individually several times over and over again until they worked):
first i deactivated my computer in the line6 authentication system. (it took a long time until I even found out that something like this exists and then I had to find it)
then i did a basic uninstall of hx edit and helix native.
since that wasn't enough on the first try, i had to go deep into the file and registration system of mac on the next attempts, remove helix-native entries in various system and user library folders, and delete the plugins individually.
but this still didn't work:
unfortunately you also had to delete the user folder (renaming it wasn't enough - hxedit automatically found renamed libraries) - of course i made a zip of it first.
then you had to reinstall the applications.
the first time you tried to log in, you had to turn off the firewall and be online - otherwise the application always crashed straight away.
when registering, the computer was then re-authorized via the open internet connection
after that the plugin crashed regularly again with reaper.
then i had to add the new standard user library again and remove my custom backup, which could be set up at setlist level in the meantime
in the loading menu of reaper i set the plugin as a separate process.
then I blocked the firewall again and then helix native suddenly ran
then the standard setlist was read in and when this was completed even restoring the old setlist worked.