Microsoft have this great tool that assists with issues on Office 365. As a test I didn’t patch one of my newly installed office 2013 installations and attempted to setup a profile for a mailbox hosted on Office 365. The result was endless credentials boxes being presented. Upon running this tool it identified that i was indeed missing security patches as well as not being on a supported level to open my mailbox.
Another example below is that outlook failed to start after working fine the previous day. Again the tool was run, here are the steps:
Once you have downloaded the 1MB file and run it, the tool will check for a newer version before giving you the screen above. Click on Outlook as this is where we are having a problem.
Once selected, choose the option best suited for your situation, in my case the above was chosen.
You will be asked the above question, if you choose no the Next button is greyed out so you cannot proceed.
A few checks are done, connectivity, network etc.
Once completed, the tool will try and recover/fix outlook. Follow the prompts to continue.
It detected an issue with my current profile which was there and was missing after a reboot and hence it asks to create a new one.
The tool will run and create a new profile for you with the name of email account. After this you can launch outlook and all should be fine. If not click No to go through more troubleshooting steps.
In our case it fixed the issue so we clicked Yes.
You will be asked to rate the application and provide feedback at the end.
Hope it helps.