"Shader wants tangents, but the mesh doesn't have them"

So, whenever I want to enter playmode, I get this error. I’m pretty sure that it occured when I was changing the shader of a material - but even though I changed it the error still remains. Any Ideas?

Please put your second answer as a comment, also tried to change this:

12576-shot_130628_192120.png

Please check this link Shader wants tangents, but the mesh doesn't have them - Questions & Answers - Unity Discussions