"The path "" is not a valid path to the 3.8.0-19-generic kernel headers"
I have seen this error many times when installing VMware Tools. Rerun sudo ./vmware-install.pl again. What I found out after a lot of frustration is you just say "no"
when it asks do you want to change this Since you have already installed the headers and the build environment this works for me and then I continue with the script and Tools installs. . Please keep in mind that I haven't tried this with the kernel you are using so it might not work.