Dear Google Ads API Team,
attached you find a full request and response with sensitive data removed - RequestId: jYANqslB-_D4dampbIHvhA
We already found out what causes this specific issue - which in this case is adding a listingGroup to a campaign which doesn't have a merchantCenter linked.
This operation was allowed a few weeks ago - so it seems the Ads-API silently changed its behaviour without release notes.
So the bug we found is that in this situation the Ads-Api V14 doesn't represent this error correctly and only returns a "The error is not represented in this version".
Our follow up tech question would be - are there any other undocumented changes (additionally enforced validations) done recently?
Internally such changes might be treated as bugfixes but due to the behaviour change it would be good for the users to know about them.
Best Regards,
Ronald Findling