• Completely removed old GUI handling as it was... Outdated. Remade it to run on CMI gui engine which is allot more flexible and more reliable when it comes to items being bugged out of inventory or clicking on inventory in general.
• General library updates for better plugin handling.
• API got some minor changes so plugins using old API will have to update it. Its quite minor changes, but they had to be done, check gitHub example plugin which contains full code examples.
• Some trade values changed from decimal ones to full numbers. So no more information values like 5.0 when you cant have decimal value for that type of trading.
• Now trade window title will update with some nice information when another player changes trading values. This is allot more convenient then action bar messages which can be hard to see.
• Fixed issue with Sounds not being recognized in 1.13+ servers as of new changed names
• Config file update to handle materials by names or by id and some general simplifications. So please update your config file if you had some custom values.
• Added option to define sounds used while clicking on trade window. Check config file for those ones.
• Fixed issue with new WorldGuard API changes introduced with 7.x version.

This is Experimental version, did tested out everything what i could think of to check out if its working properly with new GUI engine, but one head is always not as good as couple of them