Hi @freebluek,
maybe the knime log or the log console within the Script editor shows in which line exactly that error occurs?
It is most likely due to some missing conversion functionality in KNIME.
We are aware of it, but cannot say when we get to it. I added this thread in the corresponding ticket.
As mentioned in the above link, you might need to do a explicit conversion to ā¦ pandas? I have no idea what you are doing 
See here for an example.
Can you tweak your code like the example and tell me whether it helps? If not, please have a close look at the aforementioned knime log and the console within the script editor and provide them as well as a minimal example to reproduce the issue 
Thanks and best regards
Steffen