[Rick Erwin]

Yes, on my plane, it was during retraction and the right main gear uplock switch was out of adjustment so the system did not know all the landing gears had retracted, so the doors would not close.

In your case, I would think it would be one of the gear downlock switches.

The power circuit for the gear down green light flows from:

Nose-Right Main-Left Main-Green Light.

Check for power at each downlock switch till you find the one that’s not letting power get past it. That switch might be the source of your problem. Report back if you can ...

Rick