A little simulation

Ok xD I may have forgotten to mention that I was a beginner . But for the moment I’ve passed the part on HISM and clearly I’ve discovered that it’s extremely practical. So here I have my block of static mesh thanks to this BP: I hope its the right way to do it .

http://www.noelshack.com/2020-22-4-1590620918-hism.png

But here I try to change the material, for example the 10th mesh, but it doesnt work. I know I made a huge mistake but I don’t know where . My apologies for this blueprint horror.

http://www.noelshack.com/2020-22-4-1590620922-help.png

Rly thx for helping me <3