Hello Stephan Ricci,
I understand you're encountering a Run-time error 9 with FS Realtime on your Prepar3D v4.5 setup. This error typically indicates an issue with array indexing or referencing elements outside the bounds of an array. Here's a structured approach to troubleshoot and hopefully resolve this:
Verify FS Realtime Installation: Ensure FS Realtime is correctly installed. Reinstalling might help rectify any corrupted files.
Update Prepar3D and Windows: Check for updates for both Prepar3D v4.5 and Windows 10. Keeping software up-to-date can resolve compatibility issues.
Run as Administrator: You've done this, but it's worth reiterating as running with administrative privileges can resolve permission-related issues.
Check Compatibility Settings: Right-click the FS Realtime shortcut, go to Properties, and under the Compatibility tab, try different compatibility modes.
Examine Add-ons: If you have other add-ons installed, consider temporarily disabling them to rule out conflicts.
Review Configurations: Check FS Realtime's settings and configurations. Incorrect settings might cause such errors.
Inspect Log Files: Prepar3D and FS Realtime log files might offer clues. Look for any anomalies or errors logged around the time the issue occurs.
Community Assistance: Engage with forums dedicated to flight simulation, such as Fly Away Simulation, for insights from other enthusiasts who might have faced similar issues.
Contact Support: If all else fails, reaching out to FS Realtime's support could provide a solution tailored to your specific scenario.