Import error for import pynq.lib._video

When i am trying to run my application on the Pynq borad i get the following error:

File “/home/xilinx/boot/knn.py”, line 53, in
import pynq
File “/opt/python3.6/lib/python3.6/site-packages/pynq/init.py”, line 44, in
from . import lib
File “/opt/python3.6/lib/python3.6/site-packages/pynq/lib/init.py”, line 76, in
from . import video
File “/opt/python3.6/lib/python3.6/site-packages/pynq/lib/video.py”, line 43, in
import pynq.lib._video

Any reason why this could be happening?

More info about what you are doing would help.
Are you running this with python3?

Cathal

Thanks much for you response Cathal.

Yes i am running this on python3. when i update the image to version 2.5, the above error disappears but i am getting this new error now.
ERROR: DMASIMPLE could not find physical address for buffer - make sure the buffer is allocated with sds_alloc

Did you reburn a complete new image? Also, what code did you run the see that error message?