error: not a raw ppm file
 

I'm trying to create an animation in a curved pipe using Fluent 6.3. After running the unsteady simulation, I used Solve-Animate-define function to save the ppm files. I'm looking to create an animation of the contours of velocity. When I iterate it gives me an error when savings the files that reads
Error: ./velocity_0006.ppm: not a raw PPM file.
Error Object: ()
./velocity_0005.ppm: read error.
Anyone know what this error means. For some reason it won't save the images (the size of the file is 0)
Thanks