I try to create a mesh light based on a texture, but the texture is not shown at the viewport and the rendering. Did I something wrong or is it a bug?
yes, would be nice if this was implemented. The way I work around it is adding a simple diffuse material to the object as well to see the texture in the viewport. It gets overridden by the meshlight during rendering.
Biggest problem is that the texture isn’t shown at the rendering, so for example you can’t use it to simulate studio lights.
yes this is a know limitation with GPU rendering, for GPU your only option will be either emissive or using rectangular lights. In this particular case you can make a round area light with this texture.