Well it could be a plethora of issues creating this block.
#1 Restart your pc and do a full login including signing in and out of google
#2 Is your password expired? If it's been a while since you've set your password you can still get onto a computer but simple things like youtube and printing get blocked.
#3 Is your computer up to date? Most people take the update process for granted but if you go through all 3 steps of actually scanning for updates, the additional updates, and clearing your browser cache it really does make a difference in keeping your device running smoothly.