Help with admin panel errors. Fresh install. Mysql version issue?
You need to tweak your MySQL 5.7.5+ config for it to play nicely with Craft.

MySQL 5.7.5 changed the behaviour of the GROUP_BY statement, affecting some of the core Craft queries.

The preferred solution is to add the following to your /etc/mysql/conf.d/sql_mode.cnf file:

[mysqld]
sql_mode=STRICT_TRANS_TABLES,NO_ZERO_IN_DATE,NO_ZERO_DATE,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION


This Craft Cookbook recipe provides additional information about the problem, and the possible solutions.