First upgrade your application to Mendix 10.0.0 and then import.
You can open it on version 10 and then downgrade the metadata of the project to 9.24.3 using the MPR tool
You can change your project mpr metadata using the undocumented Mendix MprTool.
This method works fine between versions with small changes!…
This is the only way to downgrade the version and this method works fine between versions with small changes!…
Please recommend this answer as accepted if it does the job
Regards