Unable to set solar panels to action group

[Beryn]

I have no clue how I am supposed to do this.
I click the custom01 and then click the parts I want to activate, but it doesn't save, I am unable to select anything to go under group action.
Then how are you supposed to  do this?

[Streetwind]

Welcome to the forums

Are you playing in career mode? If yes, do you have the VAB/hangar upgraded enough to unlock custom action groups?

You should also be able to edit action groups in flight. Back when the feature was introduced, it always gave you full access to all action groups, even in career mode without any upgraded buildings. Not sure if that is still the case, but you can always check...

[Beryn]

Thx, Career and it is upgraded, removed them and put them on again and then it worked.
Might have done something wrong the first time, but thanks for the response.