When logging into Minecraft with a Mojang account (or a migrated Minecraft account), please be sure to use your email address, not your username, and Mojang account password
When logging into the Minecraft launcher, it asks for your username and password. However, the launcher has not yet been updated to reflect the fact that new accounts are Mojang accounts, purchased through Mojang.com, which uses your email address instead of a username.
It is also possible to receive the "too many failed logins" error when logging in with your username, instead of your Mojang account email address. If you need to reset your Mojang account password, this can be done at account.mojang.com/password.