Not using the same version. Either the files in the Cfg folder are different, or the exe version is different. Check the version in the main menu( bottom right corner ) 版本不同,包含exe檔和在cfg資料夾的檔有被修改過
Level limit is provided, and your friend do not meet the requirements 房間有等級限制
Trying to join to an online character with an offline one, or reversed "線上角色"和"角色"不能互連
Trying to join to a Hardcore game with a non hardcore character, or reversed 硬核(hardcore)角色和非硬核(non hardcore)角色不能互連
