Trying to validate a change to our Prod org, but it keeps failing with
H:\workspaces\EmergingMarkets\build.xml:19: Failed to process the request successfully. Cause(UNKNOWN_EXCEPTION): INVALID_CROSS_REFERENCE_KEY: invalid cross reference id
but the same deployment package validates just fine in our Full Copy sandbox. The only discernible difference between the two is that the sandbox is Summer 18 whereas production is Spring 18.
There's some destructiveChanges.xml before the main deployment (unravelling dependencies/references on a field API name that got renamed) that then get reinstated in the main package.xml
Any idea where to start on this one? The error message has the usual lack of detail from Salesforce.