I had it a couple of times.
Symptom: Stuck, low memory usage, no or very low cpu & disk - usage.
Solution:
- Uninstall only the Client
- DOWNLOAD a previous version of the client (for ex: Install_Client_4.2.21.24048.msi)
- RUN Prepar3D
>>> you might geht an error message maybe that a scenery file cannot be found, but this is what we want..
- P3D started successfully.
- EXIT, Uninstall the old client, and install the current one again. NOW IT WILL RUN ::))
Greetings, Stephan..