The Easy Villagers mod has a block called the Trader Block. After looking into both class files and looking at the crash log it seems like the issue might be coming from this line in your TradingDiscount class. The crash log indicates a ClassCastException when attempting to cast a ClientLevel to a ServerLevel, and it specifies that class specifically. Not entirely sure if that's something that should be fixed in the TradingDiscount class or in the OnTradesUpdated class from your library mod or an entirely different class. Never actually worked with java or I'd try fixing it and sending a PR lol. Let me know if you need other info.
Also the issue was first reported here, as far as I know.
The Easy Villagers mod has a block called the Trader Block. After looking into both class files and looking at the crash log it seems like the issue might be coming from this line in your TradingDiscount class. The crash log indicates a ClassCastException when attempting to cast a ClientLevel to a ServerLevel, and it specifies that class specifically. Not entirely sure if that's something that should be fixed in the TradingDiscount class or in the OnTradesUpdated class from your library mod or an entirely different class. Never actually worked with java or I'd try fixing it and sending a PR lol. Let me know if you need other info.
Also the issue was first reported here, as far as I know.