Hi kirantodekar,
On a quick search on the KNIME forum, I came across a similar issue with ‘PKIX path building failed’ here.
As it is mentioned in the above-mentioned post, this might be a proxy-related issue.
Here is a video that explains the issue in detail: Resolving Common KNIME Certificates Problems - YouTube.
I hope this helps to resolve your issue.
Best,
Keerthan