I used office 2010 and the structures of the equations does not work. Only a blank space shown. Then I followed
https://www.msofficeforums.com/word/...ing-stuff.html link and did all of the stuff it shown. But everything doesn't work. Then I installed office 2007 and after that 2013. But same problem appear on that

can I know the reason to happens this? If there is a way to fix this, please tell me. I use Windows 8 OS.