Common Issues

Connection issues

The file picker shows files from the wrong Microsoft account

If you have multiple Microsoft accounts, the OneDrive file picker displays files from whichever account is currently active at microsoft.com — not necessarily the one you connected in Coupler.io.

To switch accounts:

1. Close the file picker
2. Go to microsoft.com and click your profile icon
3. Sign out, then sign back in with the correct account
4. Return to Coupler.io and reopen the file picker

If you see a 103 error in OneDrive, simply close and reopen the file picker.

The file picker window doesn't open

The picker window may have opened in the background rather than closing. Check your taskbar, click your browser icon, and look for the OneDrive window — it's likely minimized.

"This workbook is not accessible through Microsoft Excel API" error

This is a known Microsoft API limitation that can affect personal OneDrive accounts. It occurs intermittently and is not caused by Coupler.io.

Try these steps in order:

1. Confirm the file is on the same OneDrive account you connected in Coupler.io
2. Disconnect and reconnect your Microsoft Excel destination
3. Try again in an Incognito/Private browser window
4. Create a brand-new .xlsx file directly in OneDrive and use that as the destination instead
5. If using a personal OneDrive, try switching to a OneDrive for Business account

If none of these work, the issue is with Microsoft's API. You can contact Microsoft Support at support.microsoft.com or consider using Google Sheets as an alternative destination.

"BrowserAuthError: popup_window_error" when connecting

This means the OAuth sign-in popup was blocked. Fix it by allowing popups for Coupler.io in your browser:

• Chrome: Settings → Privacy and security → Site Settings → Pop-ups and redirects
• Firefox: Tools → Settings → Privacy & Security → Block pop-up windows (add exception)
• Edge: Settings → Cookies and site permissions → Pop-ups and redirects

If you're on Internet Explorer, switch to Chrome, Firefox, or Edge. If your organization manages browser settings, check with your IT team about firewall or policy restrictions.

The connected Microsoft account has been deactivated

If the Microsoft account used to authenticate the destination is disabled or removed (for example, when an employee leaves), all data flows using that connection will fail.

You'll need to reconnect the destination using an active Microsoft account that has edit access to the same Excel file. Go to your data flow's Destination settings, disconnect the current account, and sign in with a valid account.

Data issues

The data flow hits Excel's row limit in Append mode

Excel supports a maximum of 1,048,576 rows per sheet. If you're using Append mode and your cumulative data across all runs exceeds this limit, the run will fail.

To avoid this, monitor your row count over time. Options include switching to a new sheet periodically, archiving old data, or switching to Replace mode if historical accumulation is no longer needed.

Numbers or dates are formatted incorrectly after import

Coupler.io writes raw values — Excel applies its own formatting based on cell format settings. If numbers appear as text or dates display unexpectedly, check the cell format in Excel (right-click → Format Cells) and adjust accordingly.

For values that need a leading apostrophe to display correctly (such as numeric strings like product codes), you can add a formula in your source data or preprocessing step to prepend a ' character.

Formulas are being overwritten on each run

Coupler.io replaces all data starting from the specified cell address, including everything to the right and below it. If your formulas are in that range, they'll be overwritten.

The fix is to reposition your formulas to the left of your imported data range, then update the Cell address setting to start your import in a column to the right of your formulas. For example, if your formulas are in column A, set your cell address to B1 or B2.

The last row of data is missing after import

If a specific row consistently doesn't appear in the destination sheet, check whether the source data actually includes that row at the time of the run. Verify the source query or filter settings aren't excluding the final record.

Permission errors

"Microsoft Excel Online temporarily unavailable" error

This error comes from Microsoft's API, not Coupler.io. It typically happens when a file contains heavy formulas or the file size makes API updates slow or impossible.

Try the following:

• Remove or simplify complex formulas in the workbook
• Reduce the overall file size (remove unused sheets, images, or pivot tables)
• Create a new, clean Excel workbook as the destination and re-run the data flow

409 error — resource conflict

A 409 error means two write operations are conflicting. This usually happens when multiple data flows write to the same file at the same time, or when a data flow is triggered multiple times before the previous run finishes.

To prevent this:

• Stagger the schedules of data flows that write to the same workbook
• Avoid manually triggering a run while another is already in progress
• Don't edit the file in Excel while a data flow is running