What is this error message?
 

Hi, I'm using Ansys 15 ver

Recently I received this error message during calculation. Data and case files were saved until that error appeared.
But, after that massage apeared, the solution tab did not change from lightning to check mark. And then I couldn't read the data normally when I opened the fluent-solution tab again.
and the solving data were initialized , so I had to save data files in other folder temporarily.
This problem has been continued since the recent windows update.

How can we solve this problem? This is so exhausting. Please help me


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System.InvalidOperationException: Collection was modified; enumeration operation may not execute.

at System.ThrowHelper.ThrowInvalidOperationException( ExceptionResource resource)
at System.Collections.Generic.Dictionary`2.KeyCollect ion.Enumerator.MoveNext()
at Ansys.Fluent.Data.SolutionListManager.IsFinalSolut ion(Int32 iteration)
at Ansys.Fluent.Data.SolutionData.IsIntermediateResul t(IReadLockContainer context)
at Ansys.Fluent.Query.GetSolutionStatusQuery.Execute( IQueryContext context)
at Ansys.Core.Commands.Concurrency.QueryWorkUnit.exec uteInContext(CommandContext subContext, IExecutionEngineCallback tracer)
at Ansys.Core.Commands.Concurrency.BaseWorkUnit.doExe cute(IExecutionEngineCallback executionEngine, CommandContext subContext)
at Ansys.Core.Commands.Concurrency.BaseWorkUnit.Execu te(IExecutionEngineCallback executionEngine, Boolean dontCatchExceptions)
--- Ansys.Core.Commands.CommandFailedException: Collection was modified; enumeration operation may not execute.


CommandName: Fluent.GetSolutionStatus(Container="Solution", DefaultState={"State": Incomplete, "ComponentQuickHelpId": Some output data is not present.})
at Ansys.Core.Commands.CommandAsyncResult.RethrowFail ureException(Exception e)
at Ansys.Core.Commands.CommandAsyncResult.Wait(Int32 milliSecondsTimeout, Boolean exitContext)
at Ansys.Core.Commands.Core.OutputArgBase.Wait()
at Ansys.Core.Commands.Output`1.Get()
at Ansys.ProjectSchematic.Queries.GetComponentStateQu ery.Execute(IQueryContext context)
at Ansys.Core.Commands.Concurrency.QueryWorkUnit.exec uteInContext(CommandContext subContext, IExecutionEngineCallback tracer)
at Ansys.Core.Commands.Concurrency.BaseWorkUnit.doExe cute(IExecutionEngineCallback executionEngine, CommandContext subContext)
at Ansys.Core.Commands.Concurrency.BaseWorkUnit.Execu te(IExecutionEngineCallback executionEngine, Boolean dontCatchExceptions)
--- Ansys.Core.Commands.CommandFailedException: 컬렉션이 수정되었습니다. 열거 작업이 실행되지 않을 수도 있습니다.
CommandName: GetComponentState(Component="/Schematic/Component:Solution")
at Ansys.Core.Commands.CommandAsyncResult.RethrowFail ureException(Exception e)
at Ansys.Core.Commands.CommandAsyncResult.Wait(Int32 milliSecondsTimeout, Boolean exitContext)
at Ansys.ProjectSchematic.Queries.GetComponentStateQu ery.InvokeAndWait(IQueryContext context, DataReference Component)
at Ansys.ProjectSchematic.Queries.GetAllDisplayStates Query.Execute(IQueryContext context)
at Ansys.Core.Commands.Concurrency.QueryWorkUnit.exec uteInContext(CommandContext subContext, IExecutionEngineCallback tracer)
at Ansys.Core.Commands.Concurrency.BaseWorkUnit.doExe cute(IExecutionEngineCallback executionEngine, CommandContext subContext)
at Ansys.Core.Commands.Concurrency.BaseWorkUnit.Execu te(IExecutionEngineCallback executionEngine, Boolean dontCatchExceptions)
--- Ansys.Core.Commands.CommandFailedException: Collection was modified; enumeration operation may not execute.


CommandName: GetAllDisplayStates()
at Ansys.Core.Commands.CommandAsyncResult.RethrowFail ureException(Exception e)
at Ansys.Core.Commands.CommandAsyncResult.Wait(Int32 milliSecondsTimeout, Boolean exitContext)
at Ansys.ProjectSchematic.Queries.GetAllDisplayStates Query.InvokeAndWait(IQueryContext context)
at Ansys.ProjectSchematic.View.ProjectSchematicViewCe llStateEngine.UpdateStates(Boolean setStates)