How to solve the error message when starting users and groups in linux

Article Title: how to solve the error message when users and groups are started in linux. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source.

When I try to start system-config-users I get the following msg:

"The user database cannot be read. this problem is most likely caused by a mismatch between/etc/passwd and/etc/shadow or/etc/group and/etc/gshadow. the program will exit now."

Or

A key will appear when you set it. Click it to report:

"You're currently authorized to configure system-wide setting (that affect all users) withou typing the administrator password again. You can give up this authorization"

They discuss world issues and look for solutions:

I had deleted a user from my password file using vi. apprently the group was still exesting so it was giving errors loading. to fix this

I went to command line and

Groupdel test <-- test is the user I deleted from/etc/passwd using vi

Useradd test

Works fine now