I cant login in laucher.

Put the summary of the bug you're having here

What I expected to happen was...:
I dont now.

What actually happened was...:
One day I was playing minecraft, the next day I started the launcher and had to log in again. I entered the data correctly but after several attempts I still beat error:
SORRY, BUT WE COULDN'T CONNECT TO OUR SERVERS.

Please make sure that you are online and that Minecraft is not blocked

(Sun Cert Path Builder Exception: unable to find valid certification path to requested target).
Please help how to fix it.

Steps to Reproduce:
1. Run the launcher.
2. Enter the account information
3. Click Log in.