console errors different from monodevelop

My Unity Console errors are different from the errors found in MonoDevelop-Unity. Why is this happening? Which errors would be critical to be able to run the application?

If this helps, I upgraded a Unity version 3.5 project to version 5. Now I’m just trying to solve issues in order to still be able to run the same application. Would this impossible?

What I reccommend you do is just listen to the Unity Console. That’s what I do when I recieve errors using MonoDevelop. However, I now use Microsoft visual studio because it suggests error fixes and stuff like that without going into unity and waiting for the scripts to compile.