From here.

Yesterday I got the “NS_ERROR_FAILURE (0x80004005)” error when starting a VM instance in VirtualBox. Reinstalling didn’t work and the error was still there. The real problem is the security permission. Go to “System Preferences -> Security & Privacy”, confirm the permission needed by VirtualBox, then the problem is solved.

From here.

The goal is to use “pandoc” to convert a given html page to a PDF file.

From here, here, here and here.

From here.

From here.

From here and here.