If you are like me and refuse to like the new Youtube Material Design look there is an easy way to revert to the original look that works at least for the moment. First up if you are signed in to Google you will have to sign out.
Open a Youtube page and locate the Three dots immediately to the left of the sign in logo, and on the drop down menu select Restore Old Youtube.
You can then tell youtube what you think of the new theme on the newly opened dialogue box but unfortunately you have to select one of the options for the new setting to take place. The old Youtube interface will remain now whether you sign back in or not.
You may also find going back to the old Youtube theme will restore the ability for any download add-ons to work again. Only for non copyrighted videos of course
Open a Youtube page and locate the Three dots immediately to the left of the sign in logo, and on the drop down menu select Restore Old Youtube.
You can then tell youtube what you think of the new theme on the newly opened dialogue box but unfortunately you have to select one of the options for the new setting to take place. The old Youtube interface will remain now whether you sign back in or not.
You may also find going back to the old Youtube theme will restore the ability for any download add-ons to work again. Only for non copyrighted videos of course