Error 500 when activating plugins

Hi whenever I activate the recommended plugins for the altitude theme, my site losses functionality and I receive error 500. I am forced to deactivate the plugins via MyPhp to regain any access. What is the best recommended course of action to fully utilize my new theme and not loose access to my website?
Most recently the plugins that caused me issues are HGR megamenu, megafooter hgr extender and revolution slider.I currently only have one plugin active, visual composer, and everything seems to be running smoothly.