Created attachment 1482398 [details]
troubleshoot.log as exported from the print problem diagnostic tool

Description of problem:

I bought an HP OfficeJet Pro 6970. The printer works both as a network printer or attached to the computer via USB.

When printing with the recommended hpcups driver, the job prints fine with good results. However, at the end of the job, a error messagebox appears, saying the print job failed ("Print Error There was a problem processing document ..."). The Diagnose button only suggests looking at the journal entries.

When inspecting the attributes of the failed job via the GUI, I notice the value `job-printer-state-message` set to "Filter failed". The job has to be explicitly deleted to remove it from the job list.


Version-Release number of selected component (if applicable):

hplip is version 3.18.6-1.fc28 .


How reproducible:

Always, as far as I can tell. With the printer set up as a network printer, I got the above behavior for the test page in the printer configuration, when printing a web page from Firefox or when printing a PDF from the command line with `lp`.


Steps to Reproduce:
1. Use `system-config-printer` to add the printer as a network printer (adding it as a USB printer reproduces the bug as well). Choose the suggested printer and then the recommended driver ("HP Officejet Pro 6970, hpcups 3.18.6 [en] (recommended)").
2. Adjust printer options (e. g. page format) as necessary.
3. Print test page.
4. The page prints fine, but a messagebox appears saying there was a problem. Jobs must be removed explicitly.


Actual results:

See description.


Expected results:

The job should print without error messages. Finished jobs should be removed from the job queue automatically.


Additional info:

I tried the following to find out more and potentially get rid of the problem:

- Installed the printer as an USB printer, not a network printer. The problem still occurred.
- Set up the printer with `hp-setup` (worked only as a USB printer). The problem still occurred.
- Deactivated firewall and SELinux (set to not enforcing) before printing. The problem still occurred.
- In addition to printing the test page from `system-config-printer`, printed a web page from Firefox and a PDF from the command line with `lp`. The problem still occurred in all these cases.
- Tried the second driver for the printer ("Generic PCL 3 Printer Foomatic/pcl3 (recommended)"). The error message after printing disappeared, but the test page looks awful.
- Tried the third driver for the printer ("HP Officejet Pro 6970 hpijs, 3.18.6"). The error message after printing disappeared and the output looks fine, but often (or always?) the printer ejects a blank page after the job.
- With the first, recommended, driver used https://fedoraproject.org/wiki/How_to_debug_printing_problems#Getting_debug_logging_from_journal to enable debug logging (later changed this to log level `debug2` in `cupsd.conf` and restarted cups). I got the message, "Job stopped due to filter errors; please consult the error_log file for details.", but there were no specific messages that hinted at which filter caused the problem (I found nothing in the journal or in `error_log`). I'm going to attach the log output for one of the failed print jobs.

At the moment I don't have a workaround that allows me to ignore the problem. Either I have to "click away" the error message or I have to sort out blank pages after printing. Even if noone knows a proper fix, I'd be thankful for a way to at least silence the error, so I don't have to confirm it everytime I print.