Cant assing crew to any vessel

[Commodore_32]

This is simple, whatever vessel it is I can't put or quit crew from it.

This is horrible because in testing I go for remote control, but if the root part was for example a Mk3 Cockpit i cant get the crew out, and the vessels designed for transport crew I can't get kerbals into it.

If I open Alt+F12 in the console tab it keeps saying this:

NullReferenceException : Object reference not set to an instance of an object.

If you ask how it doesnt let me choose crew it is just when I click the red cross it does nothing and the exception appears.

When I click the green button it does the same and when i drag the icons to a place (like another part) and let it go it teleports to its original place.

Any idea?

Edited September 27, 2020 by Commodore_32
Grammar

[Commodore_32]

Well, still can't find the solution to this.

But I tried in another save, and that worked. Without exceptions and no errors, I need help to fix that in the other save.

[Zoeille]

I have the same issue :'(