Get Started with the ISV Customer Debugger
The ISV debugging capability covers a gap in what you can do with the Apex Debugger. As an ISV, you can debug
your own code. As a subscriber, you can debug your own code. However, because of the protections
against seeing managed code, subscribers can’t debug ISV code in their orgs.
With the ISV Customer Debugger, an ISV can work with a subscriber to debug issues specific to the subscriber’s org. An ISV can reproduce issues in the specific environment, so problems can be diagnosed more quickly, facilitating faster fixes for the ISV’s software offering. You can debug only sandbox orgs.