Incorrect hyperlinks on calendar's days


I have installed Group Calendar, made some events and try to click them (see atachment), but links has strange very long url like this:

Jumping by this url gives me Error 406 in my browser:
Error 406 - Not Acceptable
An error has occurred. Generally a 406 error is caused because a request has been blocked by Mod Security. If you believe that your request has been blocked by mistake please contact the web site owner.

I disabled all plugins related to antispam but issue still happens. How can I fix calendar's day urls ?