unity Ensure Read/Write is enabled

Error because your image has not been marked as enabled

Here's how to fix it

Hope you will fix your mistake

I've got the same error, but with a different reason, so I'd like to share to help others that can get stuck in the same situation:

Cause

1. I was using a Cone shape for particle emission (Shape tab)
2. By my own mistake, I selected Texture Default-ParticleSystem
3. I don't know exactly why, but these Unity Default textures always cause the discussed error
4. In this case it's tricky to find, because Unity doesn't clearly tell which texture is wrongly set (from the Render tab or from the Shape tab).

Solution

1. I've just removed the Shape Texture setting it to "None" then the error disappeared