You can't add this user as an admin because they are in the Removed Users list and you can'tare not allowed to unban them.
117
抱歉，您不能將此用户委任為管理員，因為對方已被封鎖，但您沒有足夠權限為對方解除封鎖。
42/117
Tony Wong,
Feb 17, 2019 at 16:11
抱歉，您不能將此用户戶委任為管理員，因為對方已被封鎖，但您沒有足夠權限為對方解除封鎖。
42/117
Tony Wong,
Dec 24, 2018 at 19:43