Hi @ma77yd07ca1m , thanks a lot for the spindump.
Now the case is clear, the vstscannermaster is stuck in an endless recursion. Please have a look in the folder
/Library/Audio/Plug-ins/VST3
Inside that folder is an item called VST3 which is actually a symbolic link to the VST3 folder you are currently in. As the vstscannermaster goes through the file tree, that link recurses to always the same VST3 folder, thus the scanner never comes to an end.
Please delete that symbolic link, kill any process with VST in the name and then try again starting Dorico