Saving material

Yes, so at least you have the material as a fixed int from an array. That’s a good start.

If all the BPs also had their own ID, then you have everything you need to do it with the default UE save game. You’d need a little bit of code to set the IDs, just get all actors of class and then set ID, but you’d need to do that in the level BP as an editor mode custom event. If you don’t know about that it’s probably quicker to get the plugin working, but I’m afraid I haven’t used it.

EDIT: Ok, I read the docs. You just mark the variables for saving.

Then you need to use those blueprint nodes ( in the quick start ) to do the actual save and load. Did you do that?

PS: Place to offer jobs is: https://forums.unrealengine.com/community/got-skills-looking-for-talent/job-offerings