'Invalid username or password' when trying to log into Mobility Print

This article helps you troubleshoot those frustrating “Invalid username or password” errors in Mobility Print.

Despite what the message says, the problem isn’t always the password. It could be a sync issue, a server connection problem, or just a user clicking the wrong link. This guide breaks down the most common causes—whether it’s an end-user, an admin, or even the built-in account—and what to check in each case.

Users can’t log in to the Mobility Print client

First, rule out any problems with the user’s account in PaperCut NG or MF.

1. Have the user go to the User Web Interface for PaperCut NG/MF:
   http://<your-papercut-server>:9191/user
2. Ask them to log in with their usual username and password.
   • If they can’t log in here, the issue is unrelated to Mobility Print. It’s likely a sync or account issue. See: “Invalid Username or Password” when users log into PaperCut NG or MF .
   • If they can log in here but not in the Mobility Print client, collect logs from the client device and send them to your support contact: .
     How to capture Mobility Print logs .
     

Users can’t log in to the Mobility Print web interface

This one’s expected behavior for most users. Mobility Print’s web interface is for administrators only.

If end-users see “Invalid username or password” it usually means they’ve:

• Opened the Mobility Print server address (e.g. http://servername:9163) in a browser
• Tried to log in using their own credentials

Can’t log in with built-in admin account

If you’re using the built-in admin login and see this error:

• Double-check the username and password—especially if this is only affecting one admin.
• Make sure Num Lock or Caps Lock isn’t interfering.
• Try resetting the admin password following this guide: Change the Mobility Print server password .

Can’t log in with NG or MF admin accounts

Mobility Print relies on the PaperCut NG/MF server to authenticate users. If the main server is down, port 9192 is blocked, there’s a misconfiguration in the print-provider.conf file, or the PaperCut server can’t reach the external user directory, admins may see “Invalid username or password” when logging in.

Things to check:

• Check the Application server: Make sure the PaperCut NG/MF Primary Application Server is running. Log into the PaperCut server and open a browser to http://localhost:9191. If that doesn’t load, see Application Server fails to start .
  
• Test the certificate and port 9192: Ensure the PaperCut NG/MF server has a valid certificate installed and is listening on port 9192. We’ve seen many times that a customer fails to install a certificate properly, and the NG/MF server stops listening on port 9192. To test, from the Mobility Print server, open a browser and go to https://<papercut-server-IP>:9192. If that fails, see No access to the web interface .
  
• Verify server address config: Check that the print-provider.conf file on the Mobility Print server has the correct hostname or IP address for the PaperCut server. On a 64-bit Windows system, this file is usually located at C:\Program Files\PaperCut MF\providers\print\win\print-provider.conf.
  
• Confirm login at NG/MF web interface: You can log in directly to the PaperCut NG/MF web interface at http://<your-papercut-server>:9191. If this login fails too, the issue isn’t with Mobility Print—it’s likely a problem with syncing or the user account. See Troubleshooting end-user login issues .

Further troubleshooting

If you’ve worked through the steps above and users still see “Invalid username or password,” it’s time to gather more information.

We recommend collecting the following logs and sharing them with your PaperCut support contact.

• Mobility Print server logs (will need to be downloaded manually)
  • Windows: C:\\Program Files (x86)\\PaperCut Mobility Print\\data\\logs\\pc-mobility-print.log
  • Mac: /Applications/PaperCut Mobility Print/data/logs/pc-mobility-print.log
  • Linux: /home/papercut/pc-mobility-print/data/logs
    
• PaperCut NG/MF Application Server debug logs.
  • See How to collect the diagnostic bundle .

Your PaperCut support contact will use these logs to identify what’s going wrong behind the scenes and help you get things working again.