Outlook Disconnected for one user out of 4 Office 365 Professional

One client of 4 Office 365 Professional is disconnected via outlook.

I can connect to the account via OWA but no luck with Outlook.

I have tried to set up the account in question on a different machine and i get the following error.

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Tests from https://www.testexchangeconnectivity.com show the following errors

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	The attempt to ping the endpoint failed.
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	Image may be NSFW. Clik here to view. Additional Details   The RPC_S_SERVER_UNAVAILABLE error (0x6ba) was thrown by the RPC Runtime process.

The service health shows everything is  A ok??

Help?