blank box on Access Control

Hello everybody!
When I click ‘Access Control’, on the right, I don’t see the roles I set up nor the users. There’s only a blank box.
I don’t know what happened since it used to work.

Is there anybody willing to help me out that knows how to fix it? Pleease!

Thanks!
Quebro

https://ww.wp.xz.cn/plugins/advanced-access-manager/