Hotmail issues on Apple devices

In the past month I have boughtt a new iPad and Macbook. Already had an iPhone. My hotmail account worked fine on my old Macbook an on my Kindle Fire and phone. Worked initially on the new ipad and macbook, but stopped working my mac. I just get a blank screen, no error messages or anything.. Seems to be working on the iPad, not sure about phone. Not all emails that show on the ipad show up on the phone. Please help!!!