If you find your layers unresponsive when they're not locked, smart, or rasterized, try this!

[Zerk31]

I was about to completely give up, revert photoshop to a previous version and/or restart my project entirely but then I found out that I somehow had the new "Artboard Tool" selected. To unselect, simply right click it and revert it back to the "Move Tool". I searched for so long for an answer and everything was wrong, but I hope this helps someone. This was such a frustrating experience as I've never encountered this in my years of working with PS. Why do they keep changing the basic tools like this?!?

[Rene Andritsch]

The Move Tool (shortcut V) is the default setting for this tool group. Maybe you hit SHIFT + V on the keyboard and activated the Artboard Tool by accident.

SHIFT + V toggles between the two tools. “V” activates only the Move Tool. You can also click and hold on the tool in the tool bar to get access to to other tools in a tool group. In this case the “Artboard Tool”.

[jane-e]

Why do they keep changing the basic tools like this?!?

By @Zerk31

The Artboard tool was released with PS 2015 and has shared space with the Move tool since then. 

I don't use it either and have moved it to the Extra Tools section by going to Edit menu > Toolbar.

https://helpx.adobe.com/photoshop/using/tools.html

Jane