Your only options are to convert the Portfolio file to a regular PDF binder (using a stand-alone tool, like this paid-for one I've created, for example: -portfolio-pdf-to-normal-pdf), or to install the latest version of Reader DC and open it there.
Your only options are to convert the Portfolio file to a regular PDF binder (using a stand-alone tool, like this paid-for one I've created, for example: -portfolio-pdf-to-normal-pdf), or to install the latest version of Reader DC and open it there.