Hello, I am having the same issue, the only thing I did before it started is to enable the multi site option, then I cleaned my cache and cookies, and than it stopped working, might have been that? How do I solve it?
I already:
1. Clear cache and cookies on browser
2. Use different browsers on different computers and even different OSes
4. Renamed plugins folder (no effect)
5. Edited wp-config and wp-login.
I can’t login since 3 days…… please someone help!!
