Sometimes a dashboard reportlet can render without data. If you experience this issue, click the title of the reportlet, which takes you to the full report.
If the full report has data, the issue is likely on Adobe's end. Have a supported user contact Customer Care to report it. If only a few reportlets are affected, it is easier to simply delete and re-create them.
If both the full report and dashboard reportlet are blank, it is likely due to reportlet settings. Check the following. It is easier to troubleshoot reportlets via its full report - once the full report is returning expected data, update or re-create the reportlet.
- Segments used: Are there any segments used that is effectively excluding all data? Try removing any applied segments to see if data returns.
- Report suite: Make sure that the correct report suite is selected.
- Date range: Ensure the date range spans a range that contains data.
- Metrics: In the full report, make sure that the right metrics are used. If needed, go to that event's report to make sure that it is being properly triggered. If calculated metrics are used, check to make sure that it is correctly defined.
- Applied filters: Try clearing the text filter in the full report in case it is excluding all line items.