After windows updates we are getting an error when using the Settings tab of a Exchange Mailbox:

System.Web.Services.Protocols.SoapException: Server was unable to process request. ---> System.Exception: Error executing 'GET_MAILBOX_GENERAL' task on '' EXCHANGE ---> System.InvalidOperationException: Client found response content type of 'text/html; charset=utf-8', but expected 'text/xml'.

 at System.Web.Services.Protocols.SoapHttpClientProtocol.ReadResponse(SoapClientMessage message, WebResponse response, Stream responseStream, Boolean asyncCall) at System.Web.Services.Protocols.SoapHttpClientProtocol.Invoke(String methodName, Object[] parameters) at SolidCP.Providers.Exchange.ExchangeServer.GetMailboxGeneralSettings(String accountName) at SolidCP.EnterpriseServer.ExchangeServerController.GetMailboxGeneralSettings(Int32 itemId, Int32 accountId) --- End of inner exception stack trace --- at SolidCP.EnterpriseServer.ExchangeServerController.GetMailboxGeneralSettings(Int32 itemId, Int32 accountId) at SolidCP.EnterpriseServer.esExchangeServer.GetMailboxGeneralSettings(Int32 itemId, Int32 accountId) --- End of inner exception stack trace ---

anyone any idea how to fix that?