Export Grid Report to XLS Displays Blank Page

I just updated to PHP7 and I’m working through a littany is problems that I’m guessing are due to missing extensions and maybe file permissions. This is on the application production server - i work in SC9 locally and everything works, so I’m trying to figure out what else I need to do on the production server to generate and download xls from Grid reports. Is there a list of extensions needed anywhere? Any other ideas?

Solved it. After updating to PHP7, I needed to re-install the php zip extension. That solved the problem.