If you’re In SharePoint Management Shell (PowerShell), you’re using the add-spSolution cmdlet, and you get this error, don’t worry, there’s a very simple fix.

More than likely, what’s causing it is the fact that within your path (-LiteralPath), you have a space or spaces (like Visual<space>Studio). All you need to do is to put double quotes around the entire path. This should quickly get rid of your error.