In Select and Mask mode the Adjustable Options panel does not pop up. All I get is a Properties panel.
I am using Win 10 and Photoshop CC latest update.
Sorry to hear that no panel is opening up when you choose "Select & Mask", could you please try resetting the preferences of Photoshop and let us know if it helps with the issue?
Preferences Reset Photoshop - https://helpx.adobe.com/photoshop/using/preferences.html
Thanks Dave. Very impressed at the speedy response - and it worked straightaway!