I did all three steps, the inventory still does not show up in the game. Also at the first mention you say 'InventoryIcons.data' and then you say InventoryIcons.json.
I generated the JSON file and it has a different syntax than the example you present here. It has more info:
{
"frame": {"x":1952,"y":768,"w":32,"h":32},
"rotated": false,
"trimmed": false,
"spriteSourceSize": {"x":0,"y":0,"w":32,"h":32},
"sourceSize": {"w":32,"h":32}
},
Also are you sure there is some step neccesarry to do you are not mentioning ? Like some plugin activation or something ?
I use the Plugin Command OpenInventory but it does not do anything.
Do you have some kind of a demo for this plugin ?