@bcworkz Tnx a lot.
Actually I put all PHP and Apache limits to infinity – so this is definitely
is not some limit on server side. I think it happens when browser tries to build this huge select with a lot of users inside. Even when I turned off all apps except the browser on my laptop – I succeed to do this task on some of the websites.
Anyway the solution for me was:
1)to update “post_author” field of all posts in “wp_posts” table where posts belonged to the users I needed to delete. So I just updated author of these posts to be the new admin I added;
2)to delete all data of the users needed to be deleted from “wp_usermeta” table; 3)to delete the users I want to delete from “wp_users” table.
I did all directly via MySQL console. So I hope I did not lose any content ))
Tnx very much for help.