How I fixed my RADS error, hope this helps

If it doesn't, I'm sorry.

Step 1) I went to my command run-thing and typed in "ipconfig" and "flushdns". Did that jazz. Step 2) Command thing again, and type "%temp%". Delete everything. There will be a few that can't be deleted, and that's fine. Step 3) Restart your computer. Step 4) Open League from the application (from the Riot Games folder idk), and not the shortcut on your desktop.

IM NOT TECH SAVVY I DON'T KNOW THE JARGON, I HOPE THIS HELPS