CMI camera stopped working after opencv & python upgrade

Hi,
Forgive me as i am new to the jetson nano. I have upgraded openCV and python to the latest versions, the USB cam is working fine, however the CMI camera is throwing the following error: (-215 error: (-215:Assertion failed) size.width>0 && size.height>0 in function ‘imshow’). When I switch the interpreter to the default system version of python (3.6) everything is working fine. Any idea what went wrong during the upgrade and how to fix it. many thanks