The dashboard went blank after one edit. Where would you look first?

Check the sources before rebuilding the chart.

A Data Studio chart was working. After a field, filter, or blend changed, it went blank. Save a copy and note the last edit so the report owner has a clear place to start.

Have them check the source tables separately for the same period. If the expected rows are there, follow how they reach the chart. If they are missing, check the source, access, and query before assuming the blend is responsible.

A blend combines reporting tables. Its join rules decide which rows match and which the combined result keeps. Here is one way a changed rule can remove the result.

What has to match?

An inner join returns only matching rows. This example requires both Campaign and Date to match. The campaign matches, but the dates do not, so no rows survive that join.

Ask which fields should connect the records and which unmatched records the report should retain. The answer depends on what the chart is meant to show. Changing the join type just to make data reappear can create a different reporting problem.

The report owner should compare the actual matching values and their formats. A shared campaign ID may work better than names if both sources genuinely use the same identifier.

Give the report owner three places to check.

1. The inputs

   Which dates and filters apply to each source table? Which fields define its rows?

2. The match

   Which fields must match, and which matching or unmatched rows should be kept?

3. The chart

   Which filters, calculations, and totals apply after the tables are combined?

Table filters act before the join; filters set on the chart act after it. Page and report filters can act at different stages, or be ignored if incompatible. Adding a field can also change how rows are grouped. The report owner needs to check the total as well as whether the chart returns.

A returned chart still needs checking.

Compare a small known slice with the source tables. Check for repeated or missing rows, the right units, and the effect of report controls. Then document the correction so the next edit has a useful reference.

A blend repair can fix reporting logic while a separate tracking question remains open. It does not establish that every inquiry was collected or that its source is known. If the collection is uncertain, review that path separately.