We’ve noticed on multiple servers (different customers) that K2 Five Exchange oAuth integration stopped working Nov 25, 2025. Note no changes to email configuration has been done. My suspicion is that MS is rolling out Exchange Server Online changes that affect K2’s oAuth integration (however, thats speculation at this point).
Anyone else running into this and any recommendations?
Receiving: SourceCode.Workflow.Shapes.EWS: Autodiscover not available and mail cannot be sent. Reconfigure K2 server with valid Exchange settings.
In the K2HostSErver.log receiving the following message (can ignore system@k2.local as that’s not the real address):
"173383731","2025-11-24 03:23:31","Error","MessageBus","61012","ConnectionError","ExchangeWebServicesOrigin","61012 Exception from message source system@k2.local: Error code: Forbidden Error description: Forbidden System.Net.WebException: The request failed with HTTP status 403: Forbidden.
at SourceCode.MessageBus.Ews.ExchangeWebServicesConnection.<>c__DisplayClass34_0.<GetNextMessageAsync>b__2(Object s, FindItemCompletedEventArgs e)
at SourceCode.MessageBus.Ews.ExchangeWebServicesConnection.<>c__DisplayClass34_0.<GetNextMessageAsync>b__2(Object s, FindItemCompletedEventArgs e)","","","VM-CapEx360:C:\Program Files\K2\Host Server\Bin","173383731","74f7dddb51274ca8847fe536611838fa",""
