NAV 2016 OData: The Active Session does not exist. Identification fields and values... error

Hi All,

I am having a problem with OData webservice. I have published standard Page 7702 as OData, and sometimes it works, and sometimes it doesn't

Sound strange but if I paste the URL into a browser (Chrome) I am getting this:

<m:error xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata"&gt;
  <m:code/>
  <m:message xml:lang="en-US">
    The Active Session does not exist. Identification fields and values: Server Instance ID='1028',Session ID='3674'
  </m:message>
</m:error>

Each time I refresh the data the value in Session ID=.... increases by one.

Sometimes after a few refreshes I am getting the expected result:

<?xml version="1.0" encoding="utf-8"?><feed xml:base="http://ph-jendev-1.jepowerhouse.com:7048/JEC2016Upgrade01/OData/&quot; xmlns="http://www.w3.org/2005/Atom&quot; xmlns:d="http://schemas.microsoft.com/ado/2007/08/dataservices&quot; xmlns:m="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata"&gt;
<id>http://ph-jendev-1.jepowerhouse.com:7048/JEC2016Upgrade01/OData/Company('JEC%202009R2')/Fields</id>
<title type="text">Fields</title><updated>2016-08-02T12:20:56Z</updated>...

One or two refreshes more and again "The Active Session does not exist" error appears

The same URL In Exprorer gives randomly or HTTP400 Bad Request, or the following (the latter more often than not):

Fields
You are viewing a feed that contains frequently updated content. When you subscribe to a feed, it is added to the Common Feed List. Updated information from the feed is automatically downloaded to your computer and can be viewed in Internet Explorer and other programs. Learn more about feeds.

Generally it seems to be "more" working in Explorer than in Chrome, but in neither of them it is 'fully' working (ie gives expected field list each time.)


The background:

The NST service runs on the box, where 4 more NST services are running. I have total of 8 NST servers hosted in one box, 3 are configured but not started, 5 are running/ 1 running NST is 2015, remaining four running are 2016 CU9.

The RTC Client can connect to the questioned service each time with no fuss.

All NST servers run o the same dedicated active directory account called NAVServer. The NAVServer account has been granted WriteSPN permissions in the domain.

All NST servers run on the same ports (mmanagement 7045, client 7046, odata 7048), they are all configured to depend on Net. Tcp Port Sharing Service.

The questioned 'fussy' service has the NTLM authentication enabled

The NAVServer account does not have Windows Admin priviledges on the server or in AD domain. But adding it to the local Administrator group on the server (and restarting the NST service) does not seem to change anything.

The SMSvcHost.exe.config includes a key added in <system.serviceModel.activation><net.tcp><allowAccounts> with the SID of the NAVServer account used to run the NST servers.

<system.serviceModel.activation>
<net.tcp listenBacklog="10" maxPendingConnections="100" maxPendingAccepts="4" receiveTimeout="00:00:30" teredoEnabled="false">
<allowAccounts>
<!-- NT AUTHORITY\NETWORK SERVICE S-1-5-20 --> <-- this is the standard one-->
<add securityIdentifier="S-1-5-20" />
<!-- NAVServer account -->
<add securityIdentifier="S-1-5-21-res-of-sid-here" /> <-- this has been added by me-->

I have also made manual URL reservations for all NST servers (using NETSH HTTP ADD URLACL URL=http://+:7046/... USER="domain\NAVServer" for each exposed service/port combination)


The CustomSettings.config looks like this (some keys removed for clarity):

<appSettings>
  <add key="NetworkProtocol" value="Default" />
  <add key="EnableSqlConnectionEncryption" value="false" />
  <add key="TrustSQLServerCertificate" value="false" />
  <add key="ClientServicesPort" value="7046" />
  <add key="SOAPServicesPort" value="7047" />
  <add key="ODataServicesPort" value="7048" />
  <add key="ManagementServicesPort" value="7045" />
  <add key="ManagementServicesEnabled" value="true" />
  <add key="ClientServicesEnabled" value="True" />
  <add key="ReportPDFFontEmbedding" value="true" />
  <add key="SOAPServicesEnabled" value="True" />
  <add key="ODataServicesEnabled" value="True" />
  <add key="SOAPServicesSSLEnabled" value="false" />
  <add key="ODataServicesSSLEnabled" value="false" />
  <add key="PublicODataBaseUrl" value="" />
  <add key="PublicSOAPBaseUrl" value="" />
  <add key="PublicWebBaseUrl" value="" />
  <add key="PublicWinBaseUrl" value="" />
  <add key="DefaultClient" value="Windows" />
  <add key="ServicesOptionFormat" value="OptionCaption" />
  <add key="ServicesLanguage" value="en-US" />
  <add key="SOAPServicesMaxMsgSize" value="1024" />
  <add key="ServicesUseNTLMAuthentication" value="True" />
  <add key="ODataServicesMaxPageSize" value="1000" />
  <add key="ClientServicesOperationTimeout" value="MaxValue" />
  <add key="ClientServicesProtectionLevel" value="EncryptAndSign" />
  <add key="MaxConcurrentCalls" value="40" />
  <add key="ClientServicesMaxConcurrentConnections" value="150" />
  <add key="ClientServicesReconnectPeriod" value="00:10:00" />
  <add key="ClientServicesMaxNumberOfOrphanedConnections" value="20" />
  <add key="ClientServicesCompressionThreshold" value="64" />
  <add key="MetadataProviderCacheSize" value="150" />
  <add key="ClientServicesMaxUploadSize" value="30" />
  <add key="EnableDebugging" value="false" />
  <add key="DebuggingAllowed" value="true" />
  <add key="ClientServicesMaxItemsInObjectGraph" value="512" />
  <add key="ClientServicesChunkSize" value="28" />
  <add key="ClientServicesCredentialType" value="Windows" />
  <add key="ClientServicesTokenSigningKey" value="" />
  <add key="ClientServicesFederationMetadataLocation" value="" />
  <add key="AppIdUri" value="" />
  <add key="ServicesCertificateThumbprint" value="" />
  <add key="ServicesCertificateValidationEnabled" value="true" />
  <add key="EnableSoftwareQualityMetrics" value="false" />
  <add key="DataCacheSize" value="9" />
  <add key="SessionEventTableRetainPeriod" value="3" />
  <add key="SqlCommandTimeout" value="00:30:00" />
  <add key="BufferedInsertEnabled" value="true" />
  <add key="DisableSmartSql" value="false" />
  <add key="DocumentServicesProvider" value="SHAREPOINTONLINE" />
  <add key="EnableFullALFunctionTracing" value="false" />
  <add key="Multitenant" value="false" />
  <add key="CloseInactiveSqlConnectionsGeneration" value="10" />
  <add key="EnableALServerFileAccess" value="true" />
  <add key="EncryptionProvider" value="LocalKeyFile" />
  <add key="ClientServicesIdleClientTimeout" value="MaxValue" />
  <add key="Binding" value="" />
  <add key="UseQueryForFind" value="False" />
  <add key="SqlParametersByOrdinal" value="True" />
  <add key="SessionEventTablePurgeLookupPeriod" value="24:00:00" />
  <add key="ResultSetGroupCacheUsesGlobalCache" value="True" />
  <add key="UseCalculatedFieldsCache" value="True" />
  <add key="UseResultSetCache" value="True" />
  <add key="EnableTempTableSizeReporting" value="False" />
  <add key="ClientBuildRestriction" value="AlwaysConnect" />
  <add key="DisableDataCache" value="False" />
  <add key="WildcardEvaluationTimeout" value="0:00:05" />
  <add key="EnableODataStrictFiltering" value="True" />
  <add key="TraceLevel" value="Normal" />

</appSettings>

I am really stuck at this point.

What else could I check or configure? Where to search for potential error logs?

Kind regards,
Slawek