Cannot launch space platform to other planets after upgrading 1.1 save to 2.0.73 + Space Age

[Demon 665.9]

After upgrading a large Factorio 1.1 save to Factorio 2.0.73 with the Space Age expansion, progression appears to be blocked at the point where travel to other planets should become available.

I have researched far enough to require travel to other planets and am able to:

Launch rockets normally

Build and supply a space platform in orbit around Nauvis

However, when attempting to launch a space platform to any other planet, the rocket will not launch.

The UI allows selecting a destination planet, and the proposed station appears correctly on the space map. The new station name is created, but its tab is always greyed out (inactive), and the rocket never launches. This occurs regardless of whether the launch is initiated from:

The space map

The main map

The “Build a new station” tab

No error message is shown.

As a result, all space platforms remain stuck in orbit around Nauvis, and it is impossible to create or send a platform anywhere else.

[Nosferatu]

That button wants to create a new platform on that planet. Which only works if you have the required industry there.

What you want to do: Enter a platform. Click on the hub.
Enter a schedule there and send it. Like a train.

[Demon 665.9]

Thank you, Nosferatu!
I was thinking wrong and making life hard on myself.
Now I feel kinda stupid, but it isn't the first time.