Crash with Mainstage 3.4

Hello everybody,

I have updated Apple Mainstage to the newest version 3.4 today and now the plugin of The Grand 3.1.25 cannot be loaded anymore. Does anybody has an idea, what to do. I already tried a reinstallation but this did not work.I already had regular issues with the plugin on older versions and this is also reported to the support (a long time ago) and support announced it to the development but nothing happened until today.

The standalone version works well.

My setup
Apple MacBook Pro 15 Mid 2015
16 GB Ram
512 GB HDD
macOS High Sierra 10.13.6

Thanks for any support!