cannot reset password

Hi there,

As the message says, something is wrong with your server, you will need to enable debug mode and/or read your server logs to see where the error is coming from and what kind of error it is. Enable debug https://codex.ww.wp.xz.cn/Debugging_in_WordPress, once you’ve found the error, let me know so I can better understand what’s going on. It’s highly unlikely the issue is caused by WPUM though.