Try uninstalling Support Assist which will eliminate the error message. The forum post you referred to is correct. It is due to the proprietary nature of Dell connections and nothing to be concerned about. Also a lovely case and highly recommended in reviews.
Ever since I changed my case and power supply, I am getting this error message during the BIOS diagnostics: Error code 2000-0716   [IMAGE]   My computer is all turning up and running fine. Power and reset - both buttons work as expected. I followed this link: [URL] to attach the cables to the motherboard. Two power LED(+ve and -ve)-I didn't connect as they are not on the Computer case. My case is this: IAN LI LANCOOL II MESH PEROFRMANCE BLACK Tempered Glass ATX Case -Black Color -LANCOOL II MESH PEFORMANCE-X     If I follow this post: [URL]#M47725 then there is nothing to worry. Does somebody knows how to suppress this BIOS diagnostics and if needed, how to bring it back? I have dual boot Windows 10 and Ubuntu Linux - so I don't want this diagnostics which expects me to click continue. My case is this: [URL]  
Dell diagnostics - power button cable failure