Blender doesn`t render object I have an issue , I tried to google it and find it here on the topics but with no luck. The issue is that my object isnt`t rendered if I press the view port shading on "rendered" icon, but it does render if I press the Render active scene in the right side tab under render options. It renders other objects in other files just fine , but not this one. It rendered normal like 10 min ago, now nothing. In the left side where it shows the render time it just says  it took less than 1 sec to render. Btw my light source is a panel with emission. I also tried to add other light sources but with no change. What could be the issue ? 
thx
I don't know it is your case, but I think you have a Render Border.

Go to View Clear Render Border. 

See the image below.