Summary Links Web Part Error 0x80070002

When attempting to add a summary links web part, you may receive the following 0x80070002 error: Unable to add selected web part(s).  Could not load XSL file.  The system cannot find the file specified. (Exception from HRESULT: 0x80070002) There are a few possible solutions to this problem.  Let's start with the simplest! NOTE: The information [...]