The command is
/execute @a[score_Zombie_min=10] ~ ~ ~ /setblock 8810 40 8843 minecraft:redstone_block
I've tried @p and I tried it with and without the / in front of setblock. So far the command hasn't place a single redstone block. I'm not really sure how to get it to work anymore. The chunk is loaded. All the commands and what it is doing it in less then a 50 block radius. I have tested all other commands on their own and they all run fine. Oh the server I'm trying to set this up on is a 1.12.2 server. Can someone please help me?