Logic Pro 11.1.2 and iMovie not booting since Sequoia 15.4

Logic Pro crashed during a sound-Library update and is not booting, same issue with iMovie: compatible Files do not open and new files cannot be started since 3months. The standard Apple Troubleshooting did not give a solution and the support does not want to understand the subject. Unfortunately, the open posts for this issues are closed without solving and without comments. The new Macbook M3, working with lightspeed, cannot be the issue; my old 2017 Intel iMac with Ventura does not have the slightest difficulties. Anybody else having this difficulties too? Perhaps there is a working bugfix, otherwise I will have to change to non-Apple software solutions...