Plugins like Yoast and Slider Revolution don't set PRIMARY KEY on tables when they are created. This is an issue when using services like Digital Ocean managed databases etc.
By installing this plugin it will add a query filter and look for queries that include CREATE TABLE and UNIQUE KEY, but not PRIMARY KEY, and insert a PRIMARY KEY for the same field as the UNIQUE KEY.
Install directly from the WordPress plugin repository at https://wordpress.org/plugins/primary-key-fixer/.
Note: It's important that you install this plugin before any of the other plugins as the 'create table' queries are run during install.