So I've been working on a server powered by command blocks for me and my friends, but when I try doing an execute command, I get this output in the console and in the command block.

[08:03:53] All invocations failed: '/execute @e[tag=chair2,r=1] ~ ~ ~ /summon item ~ ~1 ~ {Item:{id:"minecraft:spawn_egg",Damage:91,Count:1b,tag:{display:{Name:"Chair",Lore:["Module: Household","Furniture and Objects"]},EntityTag:{id:"minecraft:sheep",CustomName:"SpawnChair"}}}'

I've had this error before when I was trying to get command blocks to run plugins commands before looking up that it is impossible.

Plugins I have are ViaVersion, WorldEdit and NCP.