ZOPSignCmd Extensions Not Loading In Photoshop CC 2014 Windows

Question

I have an unexpected problem. I have been redeploying my Configurator extensions into HTML5 extensions for Photoshop CC 2014.
I have two extensions that are packaged together using Davide Barranca's excellent tutorial on how to package extensions (http://www.davidebarranca.com/2014/05/html-panels-tips-10-packaging-zxp-installers/).
If I install the two extensions separately, they both install into Photoshop. If I package the extensions together in a ZXP file, Extension Manager CC shows that they have been installed, but when I open Photoshop CC 2014, Extensions is grayed out (this is on Windows 7). When I take the same extension package and try to install on a Mac into Photoshop CC 2014, they install fine.
What is strange about the above is two weeks ago I was doing the same thing and the packaged ZXP file installed fine into Windows 7 Photoshop CC 2014 (I have made some changes to the extensions and this is why I am re-testing them).
The only change that has occurred between the two versions is some re-editing of the postscripts.jsx file. Everything else is the same including the MXI file.
I am not a Windows person, so I am at a complete loss as to why something worked and now is not working.
If anyone can give me some insight into what is happening I would be eternally grateful.
Sam

Answer 1

In the Windows 7 computer I just have Photoshop CC 2014 no Photoshop CC.
I tried this below and it did not install the two extension even though the Extension Manager CC said they were installed.
    <files>
        <!-- The HTML panel, for 15.0 onwards -->
        <file source="SEZI/com.smilepix.sezi.zxp"
              destination="$adobecommon/CEPServiceManager4/extensions" platform="mac"
              file-type="CSXS"
              products="Photoshop,Photoshop32,Photoshop64"
              minVersion="14.0" maxVersion="15.0" />
        <file source="SEZI/com.smilepix.sezi.zxp"
              destination="$applicationsupport\Common Files\Adobe\CEP\extensions" platform="win"
              file-type="CSXS"
              products="Photoshop,Photoshop32,Photoshop64"
              minVersion="14.0" maxVersion="15.0" />
  <file source="LSS/com.smilepix.lss.zxp"
              destination="$adobecommon/CEPServiceManager4/extensions" platform="mac"
              file-type="CSXS"
              products="Photoshop,Photoshop32,Photoshop64"
              minVersion="14.0" maxVersion="15.0" />
        <file source="SEZI/com.smilepix.lss.zxp"
              destination="$applicationsupport\Common Files\Adobe\CEP\extensions" platform="win"
              file-type="CSXS"
              products="Photoshop,Photoshop32,Photoshop64"
              minVersion="14.0" maxVersion="15.0" />
        <!-- the entire DOCS/ folder content -->
        <file source="DOCS/"
            destination="$userhomefolder/Desktop/SEZI_EXTRAS/"
            file-type="ordinary"
            products="Photoshop,Photoshop32,Photoshop64" />
        <!-- Extension Manager icon -->
        <file source="icon.png" destination="$ExtensionSpecificEMStore" />
    </files>
The SEZI_EXTRAS folder was installed to the desktop.
Any ideas - Sam