What's the version of your Outlook 365? (File> Office Account> About Outlook). Please make sure you have upgraded your Outlook to the latest version.
From the picture you provided, it seems that the client is loading your connected services. Can these connected services be loaded successfully if you make it load for a while? If the issue still continues, since the connected services are related to your O365 account, it is suggested to sign out your account ,re-log in to your account and restart the Outlook client to see if there is any difference. You can also try to switch to other acounts and restart the Outlook client to see if it works.
In addition, as I know, the network environment may also cause similar issues. If possible, please try to switch to other network environment to see if it works.
Any update, please feel free to post back.