I know you say swagger v2.0, but can you confirm the exact version number used to build the swagger? This does chsnge and can make a diff.
Also, can you please provide more details about exactly how and when the exception manifests?
if this helped answer the post, could you please mark it as 'solved'? Also if you consider whether the title of your post is relevant? Perhaps if the post is solved, it might make sense to update the Subject header field of the post to something more descriptive? This will help people when searching for problems. Ta