The error is here:
SELECT * FROM WHERE
This should be (at a guess):
SELECT * FROM wp_users WHERE
As for what's causing that... that's a lot harder to diagnose. From the function names, I'd guess that it's a plugin that has something to do with kpg_ss, so the starting point is to de-activate that plugin if you know it.
If you don't know which plugin is causing this, deactivate all (yes all) plugins and re-activate them one-by-one until you see which one is causing the issue.
Just be aware that it could also be your theme, soyou can also try setting that to one of the default Twenty_* themes to see if that helps.