In my server's commands.yml file, "unrestricted-advancements" is set to true. As i understood it, this setting was implemented to make any command executed by an advancement bypass any permissions.

I have a custom advancement pack which works 100% on a vanilla minecraft server (no spigot/bukkit), but when I put the advancement pack on a server which only has a clean install of spigot, I get an error stating "I'm sorry, but you do not have permission to perform this command. Please contact the server administrator if you believe this is in error."

The advancement in question checks if a player has a full inventory of logs by summoning an area_effect_cloud to run a clear command in order to use the /stats command to check if the player has a full inventory of logs via scoreboards. I have attached the function in question to this post.

Without "unrestricted-advancements" working, the custom advancements are broken, so i've marked this as major due to their being no workaround.