Today mid flight with my P3P I had a "Warning Motor Obstructed" message pop up.  I immediately brought it back and landed.  I felt all motors and they were all the same temp and not hot.  They all spun freely by hand.  I restarted the motors and let it hover and it sounded normal and hovered fine.  I flew it a bit more after that and the message never came back.  The drone was never landed hard or crashed.  The blades all appear to be in good shape.  When hovering close to me I did notice the gimbal was vibrating a little, almost like a blade balancing issue.  I have a spare set of blades and can try those tomorrow to see if that makes a difference with the vibration.  Would a slight vibration cause this warning to pop up?  I did a search and everything I found regarding this issue seams to be related to a crash which mine has never experienced.  Any ideas?  

The sensors in the aircraft monitor almost every part of it. If you see the gimbal vibrating some, then it could be because of a prop.
Have you ever dinked a prop on the ground or anything at all?
'm betting that when you fly with new props you will not get the message anymore as long as you said the motors spun free and you didn't feel any resistance.
Also, if you ever fly from dirt, you should blow out the motors and the aircraft with some low pressure compressed air.