I have a project based closely on the java web app sample. When attempting to redeem the auth code for a token it occasionally fails. However instead of reporting a AD exception it encounters a NullPointerException within the logging step: AuthenticationResultSupplier.logException(AuthenticationResultSupplier.java:139.
Stack trace: msal4j nullpointer.txt

I am using v1.5.0 but based on v1.6.1 the issue appears to be that MsalClientException does not have an error code in that scenario and fails comparison.