Just to be doubly sure, can you confirm your FSX.exe properties look like this?

It seems not all files are installing properly. This is usually caused by insufficient privileges.
Event using admin, writing file in default windows "program files" will need another privilege.
My suggestion is to reinstall FSX, put outside windows default schema. i.e C:FSX

Can you confirm that you are running the installer as admin?

Update: MV has an update on their forum which fixes the dark panels

I understand that MV will be fixing this issue in a future update

Does this happen with 2D popup in other aircraft?
We have tried to replicate this issue but have not been able to. We suggest that that you do a complete uninstall - reinstall and ensure the KingNav is setup correctly in the configuration menu

We have tested and can replicate your issue. We believe there is something going on in the 310 redux. Have you talked to ?? If so, what did they say?

We will also contact them.

We need to determine whether this is caused by the 310 or the KN. Can you please check your KingNav with your default aircraft and report back here with the results?

Thank you