Incompatibility with the editor

[TipoRick]

Tested server: Purpur 1.21.7
Plugin version: Latest

1. If in the editor (https://minecraft-inventory-builder.com/builder/inventory/20254#builder)
   to specify as an icon the portal of the nether, then when loading on the server the menu will not work

2. With such a problem, the plugin does not even indicate what the reason is, referring to incorrect syntax, and it is possible to find the problem by a layman only by poking