Power Automate Approvals not working!

same issue

The fall back option of going to......

• Go to https://make.powerautomate.com → Action items → Approvals and approve/reject from there. This bypasses issues with broken or invalid email links.

.....does not work as this also produces an authentication error

I can get to the flows via Power Apps BUT Power automate is very slow to load and then has the authentication failure

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Hello Sophie Burgess

Based on the behavior you described (users receiving an “Authentication failed” error when clicking the approval link), this issue may be related to an authentication problem affecting Power Automate approval experiences.

As an immediate workaround, please ask affected approvers to try clearing their browser cache, cookies, and local storage, or access the approval link using an InPrivate/Incognito browsing session to see if access can be temporarily restored.

Since this is a user‑to‑user community forum and I do not have access to backend diagnostic tools to further investigate tenant‑level authentication behavior, I recommend raising a support request from the Microsoft 365 Admin Center so that the Microsoft support team can perform a more in‑depth investigation on your environment.

Please let me know if the above workaround helps.

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Based on the provided information, the issue is with users opening approval links and receiving an authentication/404-style error page. The context covers several common causes and workarounds for Power Automate approvals failing at the point of responding.

Use the following checks and workarounds:

1. Check guest users and licensing
   If any of the approvers are guest users (external to the tenant), they cannot act on approvals unless they have a valid Power Automate license. Without this, they will not be able to view or respond to approvals, which can surface as failures when they click the link.
   • Ensure each guest approver has either a Power Automate per-user license or a Microsoft 365-based license that includes Power Automate.
2. If guest users approve via email card and see errors
   There is a known issue where guest users responding directly in the Approval Adaptive Card email receive an HTTP 403 or similar failure. The workaround is:
   • Instruct guest users to open the Power Automate portal (https://make.powerautomate.com) and complete the approval from Action items > Approvals, instead of using the action buttons in the email.
3. Verify tenant-level support for actionable messages
   If the approval is being actioned directly from Outlook (actionable message) and suddenly stops working, verify that actionable messages are still enabled at the tenant level. If these are disabled, users may see failures when clicking the approval actions.
   • Run the following in Microsoft 365 PowerShell and confirm both values are True:

          Get-OrganizationConfig | ft ConnectorsActionableMessagesEnabled,SmtpActionableMessagesEnabled
     

   • If they are False, enable them according to organizational policy and retry.
4. Use the Power Automate portal as a fallback
   Regardless of whether the failure is from Outlook, Teams, or email links, approvers can always complete approvals directly in the Power Automate portal:
   • Go to https://make.powerautomate.com → Action items → Approvals and approve/reject from there. This bypasses issues with broken or invalid email links.
5. Check for Conditional Access / Terms of Use changes
   If everything worked the previous day and suddenly all approvals fail when users follow links, an updated Conditional Access or Terms of Use policy might be blocking silent authentication for Power Automate connections. Symptoms include authentication failures and broken connections.
   • In Microsoft Entra sign-in logs, look for errors such as AADSTS50158 or AADSTS53003 for the Microsoft Flow Service resource and check the Conditional Access tab for a Terms of Use grant control with status Not Satisfied.
   • If a new Terms of Use or Conditional Access policy was added or changed, users may need to re-accept interactively, or the policy may need adjustment so that background Power Automate execution is not blocked.
6. Confirm Approvals infrastructure is healthy in the environment
   If the problem is environment-wide (all approvals failing), verify that the Approvals infrastructure is correctly provisioned:
   • In Power Platform Admin Center, confirm that the Dataverse (CDS) database for the environment exists and is in Ready state.
   • Confirm that the Approvals solutions are installed in the environment (via Power Platform Admin Center, Power Automate portal, or Power Apps portal under Solutions).
   • Ensure the flowdev@microsoft.com system user exists and is correctly configured as an application user in the environment. If it is missing or misconfigured, approvals can fail; reinstalling the Approvals solution (noting this will delete existing approval data) can recreate it.
7. If guest users are involved and email cards fail, standardize on portal-based approvals
   Because guest users have multiple known limitations (licensing requirement and email card issues), standardizing the process so that all guest approvers use the Power Automate portal to respond will avoid many of these link-related failures.

If the issue persists after these checks, collect the Session ID and timestamp from the error page (as already captured) and provide them to Microsoft Support along with confirmation of the above configuration checks.

References:

• Error when guest users approve or reject a request in the Approval Adaptive Card email
• Issues with flow approval emails in Outlook Desktop and Web
• Known issues
• Recommendations for conditional access and multifactor authentication in Microsoft Power Automate (Flow)
• Power Automate Approvals Provisioning Overview and Troubleshooting
• Power Automate Approval Dataverse provisioning errors and recommendations
• Troubleshoot known issues with forms in flows