Show diff in Snapshot Differences shows no differences.When working with Snapshot Differences, it might happen that the link Show diff shows no differences even though the calculation was completed without errors. This might happen when you are calculating the differences between two entire orgs without using partial selections.
When Copado calculates the differences, 2 attachments are created in the Snapshot Differences record. If you are calculating the differences between 2 entire orgs, the files generated might be too big and exceed the maximum size limit. The files will not be inserted and Copado won't be able to show any difference.
You can check if the files were created by overriding the VF page of the snapshot difference record and checking the Notes & Attachment related list. If you don't see the attachments with the names "source.zip" and "destination.zip" after calculating the differences, you will have to use partial selection following the best practices on this document:
This is how you can override the VF page for the snapshot difference in lightning:
1. Copy the snapshot record id from the browser url. For example XXXXXXXXXXXXXX
2. Remove everything in the url except the company domain.
3. Paste the record id adding ?nooverride=1
4. The url should look like this: https://companyDomain/XXXXXXXXXXXXXX?nooverride=1
5. Now click on the Related tab.
6. If you don't see the "source.zip" and "destination.zip" in the Notes & Attachments related list, the differences will not be shown.