Initially, you might have thought that you can add 50 variations to products in WooCommerce. This is not true, you certainly can have way more variations than that. The important part is “max 50 per run” (by default, you can add only 50 at a time) – what this means is, that you have to run it several times if your selection of attributes leads to more possible variations. How to increase WooCommerce product variations limit just define the following variable inside your:functions.php (not in wpconfig.php).
//Increase in the number of variations to 150 define( 'WC_MAX_LINKED_VARIATIONS', 100 );
Note: If you are going to increase the limit be sure your server can handle the increased limit. Because WooCommcerce set this limit to prevent memory issues.