We have identified the root cause for this issue and currently working on a fix.
Posted Apr 12, 2019 - 11:34 PDT
Update
We are continuing to investigate this issue.
Posted Apr 11, 2019 - 23:20 PDT
Investigating
We have identified an issue where Data Source Exports are not available for a subset of customers on the US Sandbox. Our internal teams are investigating with the highest priority.