I was looking thought the logs and found a line that recommended i report this to the developers

Logs:
[13:36:28.593] [.NET ThreadPool Worker/INFO] [tML]: Configuring Content: LightAndDarknessMod ([i:520][C/FFFF00:Light][C/FF0000:And][C/292929:Darkness] [C/FFFF00:光明][C/FF0000:与][C/292929:黑暗][i:521]) v0.2.0.18
[13:36:31.954] [.NET ThreadPool Worker/WARN] [tML]: [i:520][C/FFFF00:Light][C/FF0000:And][C/292929:Darkness] [C/FFFF00:光明][C/FF0000:与][C/292929:黑暗][i:521]: AshBug. You have set ModNPC.banner or ModNPC.bannerItem, but not the other. Make sure you set both, check your spelling, and that the item exists if you are using mod.ItemType(). Report this to the [i:520][C/FFFF00:Light][C/FF0000:And][C/292929:Darkness] [C/FFFF00:光明][C/FF0000:与][C/292929:黑暗][i:521] developers.