In Ideagen Internal Audit (Aura) systems configured for authentication by SSO via SAML2, users already connected and working may see this error:

Universal Time: (2022-09-18 18:21:20) Local Time: (2022-09-18 14:21:20) TimeZone: (-04:00:00 DST)
Version: 6.0.1.3
EXCEPTION: InvalidOperationException
message:   The calling thread cannot access this object because a different thread owns it.
source:    mscorlib
target:    Void HandleReturnMessage(System.Runtime.Remoting.Messaging.IMessage, System.Runtime.Remoting.Messaging.IMessage)
stack:  
Server stack trace:
 at Pentana.Tng.ServiceInspectors.LoginHelper.Login()
 at Pentana.Tng.ServiceInspectors.SAMLHelper.LoginInteractive()
 at Pentana.Tng.ServiceInspectors.SAMLMessageInspector.GetCookie(Boolean retry)
 at Pentana.Tng.ServiceInspectors.SAMLMessageInspector.BeforeSendRequest(Message& request, IClientChannel channel)
 at System.ServiceModel.Dispatcher.ImmutableClientRuntime.BeforeSendRequest(ProxyRpc& rpc)
 at System.ServiceModel.Channels.ServiceChannel.PrepareCall(ProxyOperationRuntime operation, Boolean oneway, ProxyRpc& rpc)
 at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
 at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
 at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)

Exception rethrown at [0]:
 at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
 at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
 at Pentana.Tng.Messaging.ITngService.ExecuteProcedures(RequestMessage`1 request)
 at Pentana.Tng.Agent.TngServiceProxy.ExecuteProcedures(RequestMessage`1 request)
 at Pentana.Tng.Agent.WcfProxyManager`2.ExecuteProcedures(RequestMessage`1 request)
 at Pentana.Tng.Agent.ServiceBroker.ServiceBrokerInternal.GetRemoteResponse[TRequest,TResponse](RequestMessage`1 request, ServiceMethod`2 execute)

The cause is similar to the issue described in this knowledgebase article:

Ideagen Internal Audit (Aura): Client authenticating via SAML2 closes after 30 minutes – Ideagen Internal Audit (Aura) (ideagen.com)

The same workaround should be effective in this case.