https //outlook.office.com/mail/ not working or loading - Ofiice 365 Web Outlook

I'm just sharing my thought. This might help someone. 

Office 365 web - outlook is not loading but office 365 desktop (Software Installed) outlook is working. 

When you use two browsers (chrome & IE Explorer) in the same computer  and when you are trying to open Office 365 web - outlook in both browsers at the same time it could cause that in one browser outlook won’t load. Sometimes this could happen when you use one browser as an admin and the other browser as a user. 

Solution. 

Close both browsers. Clean cache memory on web browsers. Re-open  office 365 online account and open outlook online one at a time. This worked for me.