I had the same problem.  It turns out that the directory I thought had a complete installation of matlab runtime actually only contained the installation files.  I was unable to install it, because to do that you must have root access and I don't.  There is no way to override that.  If you do have root access, you should be able to install it from the directory that you THOUGHT was the actual installation, using:

./install -mode silent -agreeToLicense yes