Common Issues

Connection issues

"Your Looker Studio is linked to [email] while Coupler.io is under another email"

Looker Studio requires the same Google account to be used in both Looker Studio and to authorize the Coupler.io connector. If these accounts differ, the connection will fail.

Fix: Log out of Looker Studio and sign back in with the same Google account you used to authorize Coupler.io. If you've recently changed your Coupler.io account owner email, you'll need to revoke the old token first:

1. Log in with the old email at Looker Studio

2. Go to your Google account's OAuth authorized applications page

3. Revoke access for Looker Studio App

4. Log back in with the new email and reauthorize the connector

This is one of the most common setup errors. Always confirm both accounts match before troubleshooting further.

"Valid data flow ID is required for execution" / Community Connector Error

This error appears in Looker Studio when the data flow ID it's trying to reference doesn't exist or is invalid — usually because the data flow was deleted after the connector was set up.

Fix: Create a new data flow in Coupler.io with a proper title, run it successfully, then reconnect the Looker Studio data source using the new data flow.

"Failed to fetch data from the underlying data set" / timeout error

Looker Studio has a 5–6 minute timeout when fetching data. If your data flow is still running or handles a very large dataset, Looker Studio may give up waiting.

Fix: Always run your Coupler.io data flow to completion before opening Looker Studio to create or refresh your report. If timeouts persist, reduce the data volume by removing unused fields or narrowing the date range in your source configuration.

"No rows or columns returned" in Looker Studio

This happens when the data flow is connected to Looker Studio before it has ever been run successfully, or when the source returned no data.

Fix: Go back to Coupler.io, verify the source is returning data, and run the data flow manually until it completes successfully. Then return to Looker Studio and refresh the data source.

Data issues

Date columns aren't recognized as dates — date range control doesn't work

This is a frequent issue. Looker Studio's date range control only works with columns that are typed as DATE or DATETIME. If your date column is coming through as text, Looker Studio won't offer it as a valid date range dimension.

Fix:

1. In your Coupler.io data flow, go to the Destination settings and click Edit

2. Check the field type for your date column — it should be DATE or DATETIME

3. If it shows as text, change the type manually

4. Make sure your source data uses ISO date format (YYYY-MM-DD or YYYY-MM-DD HH:mm)

5. Set the Date range dimension field to your chosen date column

6. Save and run the data flow again

Charts that don't use the date dimension as a chart dimension won't respond to date range filters, even if the control is set up correctly.

Old data is showing in Looker Studio even after a successful run

Looker Studio auto-refreshes its data sources every 12 hours by default. Even if Coupler.io has fetched new data, Looker Studio won't display it until its own refresh cycle runs — or until you trigger a manual refresh.

Fix: After running your Coupler.io data flow, open the Looker Studio report, click the three-dot menu, and select Refresh data. For ongoing freshness, schedule your Coupler.io data flow to run before Looker Studio's 12-hour auto-refresh window.

Date range control shows "Auto" and won't filter data correctly

The default "Auto" date range in Looker Studio may not align with your data, causing it to appear empty or unfiltered.

Fix: In your Looker Studio report, switch the date range control from Auto to Custom and set the range manually to match your data.

Exclude filters aren't removing null values as expected

Looker Studio doesn't automatically include null values in exclude filter conditions. If you exclude a value like "Closed", rows where that field is null will also remain visible unexpectedly.

Fix: Add an additional filter condition — OR [field] is Null — alongside your exclude condition to explicitly handle null rows.

Permission errors

"Could not find the requested data flow"

This error means Looker Studio is referencing a data flow that no longer exists in Coupler.io.

Fix: Create a new data flow in Coupler.io, run it successfully at least once, then reconnect it in Looker Studio by adding a new data source using the Coupler.io connector.

Deleting a data flow that is actively connected to a Looker Studio report will break the report. Always disconnect the data source in Looker Studio before deleting a data flow.