1. These are textures shown instead of your particles. In inversed colour.

2. I have also encountered the same problem as you.
The way to solve this is to deactivate/sell the flame particle texture.
Then even after you do /dl lucidspore, it still shows you the texture, right?
That's only visible for you now. The way to solve this is to go to your customs folder and there delete the flame.tga file.