How to show Variables Tab in Debug Window

I've made progress with debugging on a new project that was created from existing files as a semi-duplicate of a previous project that had some some configuration problems.  But I don't understand why I couldn't see the Variables tab earlier, and how I got it to display.  And I still have questions about the configuration differences.  Both projects have the deployed files on the same server (different subdirectories) and use PHP Remote Debug.

Earlier, I was able to debug with Project A - meaning I could stop at the first line, step into, step over, run to breakpoints, and I could see variables - in particular $_COOKIE and $_SERVER.

Project B was created fresh, from a Zip file downloaded from the open source developer site.  But I could not debug.  I think it stopped at the first line, but none of the other debug commands worked.  I wasn't able to see variables.  I didn't realize at first that not seeing the variables tab was not allowing me to see the problem, because I wasn't focusing on that.  But when I compared Project A and Project B - I noticed that the variables tab was missing for Project B. 

I don't know how I managed to get the Variables Tab visible for Project B.  Is it just automatic, and I'd managed to hide it?

When I did manage to get the variables tab to show for Project B, I could see the $_COOKIE and $_SERVER variables as with Project A.  More importantly it now turned out, I saw error messages:

• Remote file path '/var/www/ProjectARoot/index.php' is not mapped to any file path in project.
• Click to set up path mappings.

I don't know if the use of /var/www/ is normal for PhpStorm.  In any case I was able to change the path so that I can now debug. 

I think this second thing is more minor, but I don't understand what I'm seeing in Help | Settings Summary | Web Debug.  This is showing several debug servers, some of which show settings that are no longer current.