Hi Sky,

Can you provide us with your Joomla backend and FTP access so we can check on the issue directly?

this issue happens when the page has no interaction for quite a while, then try to login or logout.

see site details for dev site, and tell me the fix for live site.

Hi Sky,

I am really sorry for the delay of this reply.

The error message shown from your initial post is actually called "invalid token" but since your site language is in chinese, the error string is not get translated properly. This is actually a joomla issue and you can learn more about invalid token here, https://www.ostraining.com/blog/joomla/invalid-token/ .

You can try to add your user's session lifetime to higher value from your backend > global configuration > system > session settings, http://screencast.com/t/3RM8s8wzGhwl to reduce the possibilities of invalid token error.

Hope these help.