Node-Red in a SDCard image for another PI

Hi
I tried to backup the whole RPi2 SDCard as an image with installed NodeRed.
Then I made a second card and used this card in the same RPi. - no Problem
But when I use this card in a differend RPi (same version) node-red will not start.

I think I've read about an key (cryptkey or userkey or.... I don't remember) and do not find this site anymore.

So my question.

Do I have to change some sort of key to run an already installed node-red an different hardware (same RPi version but "only" different MAC)?
When yes, where and how?

Thank you!

Hello @goony,

I'm pretty sure I've moved sd cards between Pies and not had a problem running Node-red.

What do you see when you try and start node-red from the command line?

Thank you @jbudd

I'm so sorry.
Your right. I have a bunch of RPis all same type an version. But only one must be changed by my students to a RPi B+ :cold_face:
And I took these and placed it in a closet. So I didn't recognize. - sorry and thanks

as long as they have the same or better processor then you can generally swap cards - so swapping from an arm6 to arm7 (pi1 to pi3) should work - but swapping back from say an arm7 to an arm6 is unlikely to work.

Yes, I see. Thank you.

I just thought to remember something about using a "key" in node-red to delete it to get node-red running.
But it was some days ago and I'm not really sure.
So a the moment everything is up and running fine.
Thank you all!