Comment 2 for bug 1650775

Thank you for taking the time to report this bug and helping to make Ubuntu better.

I tried to test this on my Ubuntu 16.04 system, but the help documentation opens as expected, so I have to admit I'm not sure why it fails on your machine.

In order to automatically gather debugging information, could you please run the following command (only once) in a terminal:
apport-collect 1650775

This will add various information like the locale on your system. (Just in case you are running with some language and gnucash tries to look up the documentation translated to that language. Though even then, I would expect it to just default to the English version...)

When reporting bugs in the future please use apport by using 'ubuntu-bug' and the name of the package affected. You can learn more about this functionality at https://wiki.ubuntu.com/ReportingBugs.