I encountered the above just now as I was attempting to open the html file generated by the powercfg -ENERGY command.
My first thought was to try opening it in another browser, Chrome, to see if it can load. Result = failure. Hmm.. I did some googling and nothing substantial was discovered.
At last, I had a brainwave and concluded that perhaps there is something to do with the security in Windows system folders, as this particular html file is in the System32 folder. I copied the energy-report.html file to another directory and lo and behold, it loaded properly in the browser 😀
Apparently, my hypothesis was correct but of course, without deeper analysis it is impossible to definitively determine that it is due to the enhanced security for Windows system folders..