HPLIP Reporting Missing Plug-in after Ubuntu 14.04 LTS

I installed Ubuntu 14.04 LTS a couple of days ago and hadn't checked out my attached HP printer (M1212nf MFP). The system could see the printer, but was missing a plug-in, as shown on the highlighted line in the screenshot below.

Solution:

• Download the latest HPLIP driver from sourceforge; in my case it was version 3.14.6
• Set the *.run file you download to be executable; run it
• Run hp-doctor from a terminal to do the actual install of the required plug-in