PaperCut integrates with CUPS by hooking itself into the print workflow. By prefixing the
papercut: you’re instructing CUPS to execute a PaperCut process before passing the job into the physical printer. If after prefixing the
DeviceURI the queue immediately raises an error and enters a Stop state, the following may explain the cause:
- SELinux: SELinux is enabled on the system preventing PaperCut from working. SELinux security policies on systems such as RedHat prevent CUPS from executing foreign applications. Either ensure that SELinux is not enabled on your system, or invest in the time to understand SELinux and updated the kernel’s security policy to allow CUPS to exec the
papercut process. When this problem arises, the PaperCut backend will be unable to read the print-provider.conf file and will report this error in the CUPS
- File Permissions: PaperCut will install a CUPS backend process in the default CUPS backend directory (usually
/usr/lib/cups/backend). The installer will attempt to configure the correct permissions on the
papercut backend process. Default permissions can however vary from Linux distribution to distribution. Verify that this process has execute permissions. Copy the permissions as set on other backends in this directory such as the lpd or parallel backends.
If these suggestions fail to resolve the problem, please enable debug logging at the Print Provider layer by following the instructions in the knowledge base article linked below, and open a ticket with Support.
Also the CUPS
error_log can sometimes contain messages that are useful.