After a core WordPress update when attempting to login to WordPress website you get a white screen. After entering yourdomain.com/wp-admin in the address line of your browser you get a white screen, check to see if the phrase “/wp-admin/upgrade.php?_wp_http_referer=%2Fwp-admin%2F” is displaying in the address line.
First rename plugins file directory. If dashboard comes back then its a plugin(s) conflict. Check your plugins one at a time.
If white screen persists, it’s probably not a plugin conflict. Restore the name of plugins directory to “plugins”. Then check file “/wp-includes/version.php” $wp_db_version = [some number value] against the database options table’s options_value. They should have the same number value. If those numbers are not the same, change the value in the options table to match the value in the version.php file.
This seems to be a persistent problem for me after WordPress core updates to a BuddyPress installation.
If that is not the problem, then check your themes for a conflict.