I have created a complicated spreadsheet using excel 2007. I shared it at onedrive so some friends can download it and use it also. When they open it they are got the message that file is corrupted (they are using excel 2010-2013-2016) and some formulas and conditional format was gone at some sheets. Then I let them edit it at my onedrive and everything was working fine. It was working just fine at their browser but when they downloaded it again same message appeared. Any idea what to do ?