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Knowledgebase: WebTeam Central
KB0240 - Appointments cannot be created or updated



If you are using RealTime Services with Resource Central, WebTeam Central or Exchange Central, you are likely to experience one of the following symptoms in the relevant product:

  • Resource Central: Mail flow stops and system admins can see that appointments are not updated in the RC backend.
  • WebTeam Central: Appointments are not updated and it is impossible to create new ones
  • Exchange Central: New appointments or changes to existing appointments are not reflected in Exchange Central

And when you run the configuration test within Realtime Manager, the log will show the following error message: "The client and server cannot communicate, because they do not possess a common algorithm."



Realtime Service uses Transport Layer Security (TLS) to support connection to Office 365. As of October 31, 2018, Microsoft Office 365 will no longer support Transport Layer Security versions 1.0 and 1.1, that’s why you may experience issues when connecting to Office 365 if no upgrade is implemented.

This can also be the case for On-premise environments, where security requirements are set to TLS 1.2.

For further information on the mandatory use of TLS 1.2 in Office 365, please refer to this article:



  • If you are an Office 365 customer, you must upgrade to Realtime Service version before October 31, 2018.
  • Before the upgrading to this new version of Realtime Service, please make sure to check compatibility with your current running versions of Resource Central, Exchange Central and WebTeam Central:
    • E.g. Office 365 customers running Resource Central version 3.7.10 will no longer be supported and must upgrade the Resource Central to a higher version.



Applies to: All Realtime Service versions before

Reference: TFS #174811

Knowledge base ID: 0240

Last updated: Sep 04, 2018