Unable to access jarfile .\lib\mage-client-1.3.0.jar

Also posted on GitHub and /r/xmage, hoping that by posting here I'll hopefully get a quicker reply.
After downloading the most recent dev version (Version 1.3.0.dev2014-10-05v3) I've encountered this problem
* Open "mage-bundle-1.3.0.dev2014-10-05v3" .zip
* Open "mage-client" folder
* Open "startClientWin7.bat"
* get Java Virtual Machine Launcher error "Error: Unable to access jarfile .\lib\mage-client-1.3.0.jar"
Not very computer savvy, was wondering if anybody could offer help in "computer for dummies" terms.
After downloading the most recent dev version (Version 1.3.0.dev2014-10-05v3) I've encountered this problem
* Open "mage-bundle-1.3.0.dev2014-10-05v3" .zip
* Open "mage-client" folder
* Open "startClientWin7.bat"
* get Java Virtual Machine Launcher error "Error: Unable to access jarfile .\lib\mage-client-1.3.0.jar"
Not very computer savvy, was wondering if anybody could offer help in "computer for dummies" terms.