If you're seeing this error on your Google Data Studio reports, making all your charts breaking, you're not alone.
This is what it shows when you click on See details.
To solve it, please go to edit your report by clicking the button in the top-right corner of your Data Studio report.
Then, click the chart showing the missing data source error, and connect it to a data source, where shown below:
Then add a data source; you'll find the options in a dropdown. Data Studio will display both data sources that you already connected to your reports and others that your Google account has permissions for.
If done correctly, your chart will be connected to a data source.
Why do your charts disconnect from their data sources?
You may have accidentally removed the data source from the report.
You may have accidentally removed the data source from the chart.
When trying to create a copy of a report template, you didn't connect your account properly.
Data Studio randomly disconnects charts from their data sources (less likely, but possible).
The most common error is that you or someone else accidentally eliminated data sources on your reports, so some charts don't have any data source connected to them anymore.
But 1% of the time—which is happening recently— it's due to a Google Data Studio error.
We're noticing some users and customers reporting the "Missing data source" error when they have a connector linked to their charts.
We're currently exploring if it's an issue from our end, but it's likely to be a general Google Data Studio bug, as we've seen other providers experiencing the same issues.
The only way to solve this is pretty manual:
Connect a data source again, from scratch to your Data Studio report
Link the data source to the charts
While you will solve the problem, the solution is yet time-consuming: connecting the data source to every chart.
However, there's a trick to make it fast.
If you have too many charts you can type Ctrl+Shift and select every chart you want to link to the data source.
Google Data Studio will let you choose a data source for them in a single click:
In this image, as I've selected all these charts once, I can choose the data source for all of them, saving time.