Zeros in Returned Data

[#1]

When I run a query for a Report Suite to update a Workspace, sometimes I get all zeros back for all metrics (e.g. visits to site or visit duration). What might the cause of this? 

[#2]

It will help if you could provide more details like

1. How and where you are running the query?

2. How frequent is the issue?

3. Is there any network/console error when the data is returned as 0?