Issue

• NullPointerException on GitHub payload push AND polling to/from Jenkins
• You are getting the stacktrace described in JENKINS-26524

Environment

• CloudBees CI (CloudBees Core) on modern cloud platforms - Managed Master
• CloudBees CI (CloudBees Core) on traditional platforms - Client Master
• CloudBees Jenkins Enterprise - Managed Master
• CloudBees Jenkins Platform - Client Master
• CloudBees Jenkins Distribution
• Jenkins LTS

Resolution

The issue is related to the chromedriver plugin.
To fix the issue upgrade to the version 1.2