These events can be ignored if you have Exchange 2010.
Source: LS Storage Service
Computer: FE03.domain.com
Storage Service had an EWS Autodiscovery failure.
UnsupportedStoreException: code=
ErrorIncorrectExchangeServerVersion, reason=GetUserSettings failed, smtpAddress=User2@domain.com, Autodiscover Uri=https://autodiscover.domain.com/autodiscover/autodiscover.svc, Autodiscover WebProxy=<NULL> ---> Microsoft.Exchange.WebServices.Data.ServiceRequestException: The request failed. The remote server returned an error: (401) Unauthorized. ---> System.Net.WebException: The remote server returned an error: (401) Unauthorized.
at System.Net.HttpWebRequest.GetResponse()
at Microsoft.Exchange.WebServices.Data.EwsHttpWebRequest.Microsoft.Exchange.WebServices.Data.IEwsHttpWebRequest.GetResponse()
at Microsoft.Exchange.WebServices.Autodiscover.AutodiscoverRequest.InternalExecute()
--- End of inner exception stack trace ---
at Microsoft.Exchange.WebServices.Autodiscover.AutodiscoverRequest.InternalExecute()
at Microsoft.Exchange.WebServices.Autodiscover.AutodiscoverService.InternalGetUserSettings(List`1 smtpAddresses, List`1 settings, Nullable`1 requestedVersion, Uri& autodiscoverUrl)
at Microsoft.Exchange.WebServices.Autodiscover.AutodiscoverService.GetSettings[TGetSettingsResponseCollection,TSettingName](List`1 identities, List`1 settings, Nullable`1 requestedVersion, GetSettingsMethod`2 getSettingsMethod, Func`1 getDomainMethod)
at Microsoft.Exchange.WebServices.Autodiscover.AutodiscoverService.GetUserSettings(List`1 smtpAddresses, List`1 settings)
at Microsoft.Exchange.WebServices.Autodiscover.AutodiscoverService.InternalGetSoapUserSettings(String smtpAddress, List`1 requestedSettings)
at Microsoft.Exchange.WebServices.Autodiscover.AutodiscoverService.GetUserSettings(String userSmtpAddress, UserSettingName[] userSettingNames)
at Microsoft.Rtc.Internal.Storage.Exchange.ExchangeContext.SendGetUserSettingsRequest(StoreContext ctx, String smtpAddress)
--- End of inner exception stack trace ---
at Microsoft.Rtc.Internal.Storage.Exchange.ExchangeContext.SendGetUserSettingsRequest(StoreContext ctx, String smtpAddress)
at Microsoft.Rtc.Internal.Storage.Exchange.ExchangeContext.GetUserEwsSettings(StoreContext ctx, String smtpAddress, CacheMode cacheMode)
Cause: Autodiscovery Uri was not correctly configured or unreachable, that there is a problem with the Proxy, or other errors.
Check event details. Check autodiscovery Uri is properly configured and reachable. Check that proxy setting is properly configured and reachable. Validate Skype for Business to Exchange Autodiscovery configuration by following the trouble shooting guide. If problem persists, notify your organization's support team with the event details.