---
title: "Xerox iMFP: Authentication failure with error \"Unknown error unable to authenticate\"."
slug: "xerox-imfp-authentication-failure-with-error-unknown-error-unable-to-authenticate"
updated: 2024-04-03T10:06:06Z
published: 2024-04-03T10:06:06Z
canonical: "kb.pharos.com/xerox-imfp-authentication-failure-with-error-unknown-error-unable-to-authenticate"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://kb.pharos.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Xerox iMFP: Authentication failure with error "Unknown error unable to authenticate".

### **Question:**

When attempting to authenticate at a Xerox iMFP I receive the below error on the screen. ***“Unknown error unable to authenticate“***

---

### **Answer:**

Check that the Xerox iMFP Application Service is working as expected by using the below URL in a web browser.

[http://server_host_name/PharosXeroxiMFP/Authentication/ConvAuth.svc](http://jg-up90-mp/PharosXeroxiMFP/authentication/convauth.svc)

If this fails then check and ensure that the .NET 4.5 "HTTP Activation" feature (listed on page 8 of the installation guide) is enabled on the server.

## Related

- [Error message "Unable to connect to the Popup Server, unable to locate the port number."](/error-message-unable-to-connect-to-the-popup-server-unable-to-locate-the-port-number.md)
- [Uniprint: Unable to print zero length job errors](/uniprint-unable-to-print-zero-length-job-errors.md)
- [Unable to install Pharos iMFP onto supported Xerox printer](/unable-to-install-pharos-imfp-onto-supported-xerox-printer.md)
- [Unable to Install Popups, received error message "unable to add print processor"](/unable-to-install-popups-received-error-message-unable-to-add-print-processor.md)
- [Unable to start Pharos Database Server Service](/unable-to-start-pharos-database-server-service.md)