i have safari 9.0. suddenly today, when i right-click for a new tab, nothing??? ideas

Make sure view menu -> show tab bar is selected. You will get a + at the right hand side of the tab, you can click to add new tabs.

Safari 9.0 is not available for 10.10.5 or for Mavericks, the forum you posted in. Safari 9.0 is only available for El Capitan, Mac OS X 10.11.

Be sure you know you operating system by going to Apple menu -> About This Mac.

Safari 9.0 was made available to Mavericks on 30 Sept 2015.

Since I upgraded to Safari 9.0 every video on YouTube looks like it is Flash instead of HTML5. There is a beginning ad, the controls on the bottom of the video (i.e. gear instead of mouse-over on top left of video), pop-ups, etc. And Auto-start seems to be permanently on.

Mac mini mid 2011 OSX 10.9.5

What Rooster51 was trying to ask is this, I think: in prior versions of Safari, you could put the cursor anywhere on the tab bar, right click, and it would open a new tab. Now that no longer works: if you right click on the tab bar, nothing happens at all. In order to open a new tab, you have to go all the way over to the right to the + sign after the last tab. This might not seem like a big deal, but on the 27'' iMac screen, using your trackpad, it's a long way to move the cursor. It was much easier before when you just had to go directly above wherever you were and right click. It's a lot harder now to open a new tab.

So the question is - is there some way to set a preference or something that would bring back the ability to right click on a tab bar to open a new tab?

Try command - T.