We have multiple implementations of SharePoint together with Azure App Proxy. The whole concept has worked very well for a long time.
Now a problem has arised during content editing from Office clients. Regular web access to SharePoint and OOS editing works fine.
The SSO is working with login.microsoftonline.com but then a blank page with the SP external URL is shown and hangs:
From Azure perspective the logon is interrupted:
From a Fiddler perspective we see the following last error:
?state=AppProxyState%3a%7b%22InvalidTokenRetry
Closing the blank page will open the content but will present the following:
After pressing sign in you can edit and save the content without any problem.
I have now seen this problem on all of our implementations for different customers/tenants.
Have anyone else faced this and are aware of any workaround?
Thanks!
Martin
