So I just updated Photoshop to its newest version (2017 I believe, with the smoothing and all that) on Windows and now the opacity setting option at the bar on top has gone missing for some reason. Instead it shows a bunch of extra settings (like wet, load, and mix options), but no longer opacity. Does anyone know how I can get it back to normal?
I think i just figured it out, or at least with my similar problem. Try going to the "windows" tab. it should have a bunch of options to check or un-check. At the very bottom the "options" button made my opacity/flow/smoothing settings come back. Its worth a shot at least.
I had the same problem.
You have the Mixer Brush Tool selected. In your left-hand toolbar, click and hold on the brush tool icon until the popup list appears and select Brush Tool (at the top of the pop-up list).