Launcher stuck downloading todays patch very very slowly. Can't get the files

My launcher downloaded most of the files today at a very very slow speed, took an hour to get most of them. Now it’s stuck on the last few files for hours and it doesn’t look like it will ever complete the download.

Something is clearly very wrong. And it’s not my internet connection.

After downloading some files i got a pop up complaining about invalid certificates. Any ideas on how to fix this?