Outlook Login Problems

How to Fix Outlook Sign-In Error in SharePoint Power Apps Form

Kushani Nimanthika Oct 10, 2026 870 views

Question details

Users are unexpectedly prompted to sign in to Outlook when attempting to open a specific Power Apps form within a SharePoint list.

Fixing the Outlook Sign-In Error When Opening a SharePoint Power Apps Form

Product: SharePoint Power Apps
Device & OS: not provided
Scenario: Accessing a SharePoint list via a custom Power Apps form.
Observed behavior: Despite having correct permissions and active Power Apps licenses, opening one specific list's form triggers an Outlook sign-in prompt, whereas other lists function normally.

Before you start

Verify that all affected users have an active Power Apps license and are officially added to the SharePoint Site Members group before modifying the application settings.

Solution 1Recommended

Verify Permissions and Re-add the Outlook Connector

This resolves issues where the Outlook connector in Power Apps becomes corrupted or detached, triggering an unnecessary authentication prompt.

Often, backend changes or token expirations can cause data connectors inside a Power App to fail silently. By removing and re-adding the Office 365 Outlook connector, you refresh the authentication tokens for all users.

Check User Group Memberships

Navigate to your SharePoint site settings, go to Site Permissions, and ensure that the users experiencing the issue are part of the Site Members group.

Edit the Power App

Open the affected SharePoint list, click on 'Integrate' in the top menu, select 'Power Apps', and then click 'Customize forms' to open the Power Apps Studio.

Remove the Outlook Connector

In Power Apps Studio, click on the Data icon (cylinder shape) on the left sidebar. Locate the 'Office 365 Outlook' connector, click the ellipsis (...) next to it, and select 'Remove'.

Re-add the Connector

Click 'Add data' in the same Data panel, search for 'Outlook', and select the 'Office 365 Outlook' connector to add it back to your app.

Publish and Test

Click 'File', then 'Save', and finally 'Publish to SharePoint'. Have an affected user refresh their browser and test the form again.

Verify Permissions and Re-add the Outlook Connector

Propagation Time: It may take a few minutes for the newly published changes to propagate across all SharePoint users. Ask users to clear their browser cache if the issue persists immediately after publishing.

Solution 2

Escalate to Microsoft 365 Support

If resetting the connector does not resolve the authentication loop, the issue may stem from a known backend bug requiring administrative intervention.

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Frequently Asked Questions

Why does a SharePoint Power App ask for an Outlook login?

This typically occurs if the custom Power App utilizes an Office 365 Outlook connector to send emails, schedule meetings, or fetch calendar data. If the connection token expires or corrupts, the app will prompt the user to re-authenticate.

Do users need a specific license to view SharePoint customized forms?

Yes, users must have a valid Power Apps license or an eligible Microsoft 365 plan that includes Power Apps usage rights in order to view and interact with lists customized via Power Apps.

How long does it take for a published Power App to update in SharePoint?

Changes usually take effect within a few minutes. However, users may need to hard refresh their web browsers (Ctrl + F5) or clear their cache to force the updated customized form to load.

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