Hybrid Wizard Error - Application 'e9aa93f4-57c7-4035-bb7e-c05cf2e8da37' not found or OnPremisesPublishing is not enabled for your tenant.

Hi Oscar H. Veloz,  

Welcome to Microsoft Q&A Forum! Have a good day and I hope you're doing well! 

Thank you for sharing the details. I understand how frustrating it must be to encounter this error during the Hybrid Configuration Wizard at the Register Hybrid Agent step. It's disruptive to your workflow, especially when the portal only shows "Private Network connectors," making the cause harder to pinpoint. 

Based on my research and Microsoft documentation, the error message "Application 'e9aa93f4-57c7-4035-bb7e-c05cf2e8da37' not found or OnPremisesPublishing is not enabled for your tenant" occurs when the OnPremisesPublishing service (Microsoft Entra Application Proxy) isn't enabled or fully initialized in your tenant. The HCW relies on Application Proxy (classic) to register and operate the Exchange Hybrid Agent. The new Entra interface tends to consolidate "connectors" with Private Network features, which can make the Application Proxy section less obvious, but managing App Proxy is still handled through the "Application proxy" blade in Enterprise applications. 

The HCW attempts to register the "Microsoft Exchange Hybrid Agent" via App Proxy. If App Proxy isn't enabled (OnPremisesPublishing = disabled), the wizard can't create or locate the required application object, resulting in this error. This process doesn't use standalone "Private network connectors". It specifically requires App Proxy to be enabled docs: Enable Application Proxy. The "disappearance" of the classic App Proxy connectors is largely due to UI changes; the dashboard is still accessible directly via: entra.microsoft.com/#view/Microsoft_AAD_IAM/ApplicationProxyBlade/Overview. 

Recommended troubleshooting steps (low-risk and aligned with Microsoft's best practices): 

Verify prerequisites:  Ensure you have Global Administrator or Application Administrator permissions. Confirm Microsoft Entra ID P1 or higher licensing (P2 includes P1), with at least one user assigned the license to activate the service requirements in "Add on-premises app" section. Use the latest HCW version to avoid version-related issues download HCW. 

Enable Application Proxy (classic):  

Go to Entra admin center > Applications > Enterprise applications > Application proxy. If the menu isn't visible, access it directly: https://entra.microsoft.com/#view/Microsoft_AAD_IAM/ApplicationProxyBlade/Overview. From there, click Enable application proxy to activate the service docs: Enable Application Proxy. Note: Enabling is independent of whether a connector is installed yet, wait a few minutes for the service to initialize. 

Install and verify the connector:  

Install and verify the connector: In the Application proxy blade > Connectors, select Download connector and install it on a supported Windows Server. After installation, register it using appropriate admin credentials. Ensure your environment meets the system and network requirements, including outbound port 443 to necessary endpoints, TLS 1.2 or higher, and bypassing SSL inspection docs: Conceptual deployment plan for Application Proxy. Return to the Application proxy blade and confirm the connector shows as Active docs: Application Proxy connectors.

Rerun HCW with Hybrid Agent option: Run as administrator and sign in with Global admin credentials. If Conditional Access or MFA policies block the registration flow, temporarily relax them for the account/application during setup docs: Hybrid Agent. 

If the error persists after enabling App Proxy and confirming an Active connector:

Check for an orphaned "Microsoft Exchange Hybrid Agent" app or duplicate internal URLs with existing published apps via App Proxy delete or adjust as needed, then retry the wizard troubleshooting section in Hybrid Agent. Review Event Viewer on the connector machine: Applications and Services Logs > Microsoft > Microsoft Entra … > Connector > Admin for detailed error codes (often related to connectivity, proxy, or TLS issues). As a temporary workaround for project continuity, switch to "Classic Hybrid" configuration (publishing endpoints traditionally) in HCW until App Proxy is fully ready docs: Hybrid Agent. 

Addressing your specific questions directly: 

1. How to enable "classic Application Proxy" for Hybrid Agent registration? Enable it in Enterprise applications > Application proxy (or directly at https://entra.microsoft.com/#view/Microsoft_AAD_IAM/ApplicationProxyBlade/Overview), then install the connector from that blade and ensure it's Active docs: Add on-premises app and docs: Configure connectors.
2. How to access the "classic Application Proxy dashboard" when the portal only shows Private Network connectors? Yes, the App Proxy management dashboard is still in the "Application proxy" blade of Enterprise applications; use the direct link above. If it doesn't appear despite proper permissions and licensing, wait 10–30 minutes for service initialization or open a Microsoft Support ticket, as the tenant might not have the OnPremisesPublishing flag set correctly. 
3. Is this due to recent UI changes or tenant configuration, and how to resolve it? It's a combination of UI updates (consolidating connectors) and the App Proxy service not being enabled in your tenant. Resolve by enabling Application Proxy, verifying an Active connector, and rerunning HCW once set up, the Hybrid Agent should register normally. 

I hope the information I've shared helps clarify and partially address your issue. If you have any further questions or concerns, or if I've misunderstood or left anything unclear, feel free to let me know. I'm here to assist. 

If the answer is helpful, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".    

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.