Favorite - all items disappear

Hi, when i add items ( custom items what i have in game) to favorites they all disappear when plugin or server restart. 
I checked file in /data and it looks something is there ... 

it looks like plugin not loading favorite list from /data folder ... 

I checked this, and my favorites are loading and saving. It's possible this could be related to a specific item and incorrect JSON serialization. Please send me the data\AdminMenu\favorites.json file.

i just tested it .... i unloaded plugin, removed previous one, loaded plugin, marked my favorites with little stars in corner from all category, and after disconnect or server restart list is empty ... and it all custom items what i have on server ... 

if u need something else let me know ... 

favorites.json

Do they disappear after simply reloading the plugin? Perhaps you are testing this by adding favorites and then killing the server without first saving the server.

11 hours ago, 0xF said:

Do they disappear after simply reloading the plugin? Perhaps you are testing this by adding favorites and then killing the server without first saving the server.

yes, even after simple reload of plugin they disappear

and im kiling server, im have restart command that do server save before restart ...