Can't print any more "Stopped - Filter failed"

I assume that the printer worked before. Check your /var/spool/cups directory, and empty it.

If that does not help, see the instructions for install the necessary plugins for your HP printer here.

Im my case, it was due to missing libraries as shown by cups error log fragment:

D [07/Apr/2014:18:42:50 -0300] [Job 6] /usr/lib/cups/filter/watermarkfilter: error while loading shared libraries: libcupsimage.so.2: cannot open shared object file: No such file or directory
D [07/Apr/2014:18:42:50 -0300] [Job 6] /usr/lib/cups/filter/rastertoprinterbin: error while loading shared libraries: libcupsimage.so.2: cannot open shared object file: No such file or directory

Pay attention if your printer driver is 32 or 64 bit, so you should install the right libraries arch.

In my case, one of my kids borrowed the USB cord. Ubuntu didn't seem to know this. After I uninstalled the printer driver, I noticed the cord missing. Replace cord and driver, now works fine