To preface, I'm fairly new to Blender. I normally work in 2.8, but my current project requires me to work in 2.79.
That being said, I'm having an issue with the rendered view in Cycles. Earlier in my project, I was able to switch in & out of rendered to view my models. I'm not sure what I messed up, but now nothing is showing up when I enter rendered view. In material view, everything is visible and I can see my models just fine. But when I switch into rendered view, everything disappears including the grid.