No, Zero, everything is fine on your machine! It shows the fluid dynamic vectors (motion vectors), in real time! If nothing moves, it will look gray. Turn up Fluidity to 100% and have fun!
This is an expert feature, though, for people, who know what it's really for. You can use it (a motion vector image), for example, in compositing or on textures, to suggest or even create motion within the texture. Common use would be for water, for example. There are some free tools online to preview such motion vector textures.
Others may use it as an art tool just by itself, because it has certain special qualities. I yet have to allow to project it back into a color layer, but this all is stuff I will still do later on. For now it is mostly expert only.
But, rest assured, your computer is in perfect order, if it mostly looks gray. This "gray", by the way, is a value of 0.5 in all color channels (R, G, B). A texture shader that uses motion vector images will do a little math on it to bring this to 0.0 so that RGB values can go from -1.0 to 1.0, representing full motion vectors. Ordinary image formats do not support negative values, you know.
A shader, for example, would have a line that goes:
vec3 outMotion = 2.0*(inColor-0.5);