1) YouTube upload was fixed in Freemake Video Converter version 4.1.7. If you still have issue with wrong YouTube login or password, please update Freemake Video Converter http://www.freemake.com/free_video_converter/
2) Make sure you have YouTube account. Insert your email as login and enter a correct password.
3) If you use step two step verification in Google, please disable it.
4) If it doesn't help, please follow the steps below:
1) Go to youtube and login with your account and password.
2) From the top right choose your account settings, this is a square box to the far top right.
3) Click on your email address in the top, it is a link.
4) This will bring you to the google settings for your account and by default put you on the personal info page tab.
5) From the top choose security
6) Left hand side you will see account permissions, and then under that section the words "access for less secure apps". Click the settings link in that area.
7) Enable this setting. Make sure change is saved.