'Unable to connect to server' error when starting client

When starting the PaperCut User Client, I get an ‘Unable to connect to server’ error.

If you’re seeing a PaperCut user client error similar to one of the ones pictured below, you’re in the right place. Check through the remainder of this article to see if one of these solutions fixes your issue!

Error	Screenshot of the error
Unable to connect to the server: unable to establish connection with the server: papercutserver
Problem communicating with server: Operation timed out (Connection timed out)
Unable to establish secure connection to server: No route to host (connect failed)
(Note: you may also see a ‘Connecting…’ status if you hover over the PaperCut user client icon in the Windows task bar or macOS menu bar)

Is the Application Server running?

Check to see if the App Server is started, and if not, try restarting the App Server .

Is the connection information in the client correct?

Check the config.properties file to make sure that the server-ip and server-name lines are correct. They should show a valid IP address and hostname for your Application Server. If you’ve recently migrated your PaperCut server then you’ll need to update the connection details for the clients.

The local copy of the config.properties file can be found in one of the following locations on a workstation, assuming a default install path.

• Windows - C:\Program Files (x86)\PaperCut MF (or NG) Client\config.properties
• macOS - /Applications/PCClient.app/Contents/Resources/config.properties

Note: PCClient.app can be opened like a folder by right-clicking it and choosing to Show Package Contents

The central config.properties file can be found in one of these locations on the primary Application Server, where [app-path] is the install path of the Application Server component.

• Windows - [app-path]\client\win\config.properties
• macOS - [app-path]/client/mac/PCClient.app/Contents/Resources/config.properties

Ideally you’ll have a static IP address set up for your Application Server, so that the connection details remain the same.

Are ports 9191 and 9192 open on the Firewall?

If you’re using a Firewall in between clients and the Application Server, take a look through the Firewall Ports page to see what ports need to be opened for PaperCut to work.

As a test, open a browser Window on the client and try navigating to http://yourpapercutserver:9191 and https://yourpapercutserver:9192 (use your own PaperCut application server hostname or IP address in the URL). If this doesn’t work, try opening these ports on the firewall or disabling the firewall on the server altogether as a test.

If you’re running Windows, double check the Windows Advanced Firewall rules to make sure that the network profile (Domain/Work, Private, Public) of the network interface matches how the rule is configured. We have heard of situations where a server is restarted after Windows updates and suddenly the network type switches from the Domain Profile (less restrictive) to Private Profile (more restrictive) and the different Firewall rules prevent the PaperCut client from connecting.

Are you using “Use HTTP Strict Transport Security”?

There’s more information here on Forcing SSL , however if port 9192 or 443 isn’t open, or if you don’t have a trusted certificate installed, then the client won’t be able to connect. A good test is to navigate to https://:9192 from the client, and make sure that you can connect without any certificate errors before checking this box.

Are you using macOS 15 (Sequoia) or later?

If you’re using macOS 15+, Apple has introduced additional privacy features, including restrictions for controlling access to your local network .

If you launch the PCClient.app you will see a dialog asking if you want to “Allow “PCClient” to find devices on local networks?” You will need to click Allow, so that the User Client can connect to the Application Server.

At this point, the PCClient will exit, since it wasn’t able to successfully connect the first time. Assuming you clicked Allow, you can then re-launch the PCClient.app and the User Client should then successfully connect to the Application Server.

In the background, clicking Allow on the dialog above, adds the PCClient app into System Settings > Privacy and Security > Local Network. If you mistakenly clicked Don’t Allow, you can toggle the ability for the User Client to connect to the network here: