Error when creating GIF using images2gif.py

Error when creating GIF using images2gif.py

I'm trying to create a GIF file using images2fig.py from the visvis package
With this very simple code
import glob
from PIL import Image
from visvis.vvmovie.images2gif import writeGif
images = [Image.open(image) for image in glob.glob("*.png")]
filename = "test.gif"
writeGif(filename, images, duration=0.2)
I got an error
File "C:\Python27\lib\site-packages\visvis\vvmovie\images2gif.py", line
575, in writeGif
gifWriter.writeGifToFile(fp, images, duration, loops, xy, dispose)
File "C:\Python27\lib\site-packages\visvis\vvmovie\images2gif.py", line
436, in writeGifToFile
fp.write(globalPalette)
TypeError: must be string or buffer, not list
How do I fix this?