Table 'performance_schema.session_variables' doesn't exist.

I encountered this error in Mysql version 5.7.13 after upgrading Laragon when attempting to connect with HeidiSQL.

Here's how to fix it (from the command line):
mysql -u {user} -p
mysql> set @@global.show_compatibility_56=ON;

Replace {user} with your actual username (probably root). When it prompts for password.. enter your password.

This is a temporary fix that would need to be run once on server start.

If it fixes your issue, add this to your my.ini:

show_compatibility_56 = 1

You should already have options under [mysqld] .. append this new one to that section or modify existing entry accordingly.