TfsUserMappingTool: Sequence contains more than one matching element

[OCMarkW]

Version 16.0.4 Looks like it was validating Users between Source and Target for 7 minutes. Got System.InvalidOperationException: Sequence contains more than one matching element in TfsUserMappingTool?

This is a test run, but Source and Target are same collection as the Prod run would be.. Any ideas?

Here is the ending portion of the Log file:

[17:33:35 INF] [16.0.4] Processing Node: \ZZ-Test2\Iteration\2024\Sprint 14 (2024), start date: "2024-09-25T00:00:00.0000000", finish date: "2024-10-15T00:00:00.0000000"
[17:33:36 INF] [16.0.4] Work Item Store connected to "https://dev.azure.com/ /" with BypassRules set to true
[17:34:04 INF] [16.0.4] ----------------------------------------------
[17:34:04 INF] [16.0.4] Migrating all Teams before the Processor run.
[17:34:05 INF] [16.0.4] TfsTeamSettingsProcessor::InternalExecute: Found 44 teams in Source?
[17:34:05 INF] [16.0.4] Querying items to be migrated: SELECT [System.Id] FROM workitems WHERE [System.TeamProject] = @teamproject AND [System.AreaPath] Under 'abcxyz' AND [Tags] Contains 'Migrate' ORDER BY [System.ChangedDate] DESC ...
[17:34:05 INF] [16.0.4] Work Item Store connected to "https://.visualstudio.com/" with BypassRules set to true
[17:34:06 INF] [16.0.4] 8 Work items received, verifying
[17:34:06 INF] [16.0.4] Loading 8 Work Items
[17:34:36 INF] [16.0.4] Replay all revisions of 8 work items?
[17:34:36 INF] [16.0.4] Validating::Check all Target Work Items have the RefectedWorkItemId field
[17:34:36 INF] [16.0.4] Validating::Check that all work item types needed in the Target exist or are mapped
[17:34:36 INF] [16.0.4] Validating::Check that all Area & Iteration paths from Source have a valid mapping on Target
[17:34:42 INF] [16.0.4] Validating::Check that all users in the source exist in the target or are mapped!
[17:41:47 FTL] [16.0.4] Error while running TfsWorkItemMigrationProcessor
System.InvalidOperationException: Sequence contains more than one matching element
at System.Linq.Enumerable.SingleOrDefault[TSource](IEnumerable1 source, Func2 predicate)
at MigrationTools.Tools.TfsUserMappingTool.<>c__DisplayClass9_0.b__0(IdentityItemData sUser) in D:\a\azure-devops-migration-tools\azure-devops-migration-tools\src\MigrationTools.Clients.TfsObjectModel\Tools\TfsUserMappingTool.cs:line 156
at System.Linq.Enumerable.WhereSelectListIterator2.MoveNext() at System.Collections.Generic.List1..ctor(IEnumerable1 collection) at System.Linq.Enumerable.ToList[TSource](IEnumerable1 source)
at MigrationTools.Tools.TfsUserMappingTool.GetUsersInSourceMappedToTarget(TfsProcessor processor) in D:\a\azure-devops-migration-tools\azure-devops-migration-tools\src\MigrationTools.Clients.TfsObjectModel\Tools\TfsUserMappingTool.cs:line 156
at MigrationTools.Tools.TfsUserMappingTool.GetUsersInSourceMappedToTargetForWorkItems(TfsProcessor processor, List1 sourceWorkItems) in D:\a\azure-devops-migration-tools\azure-devops-migration-tools\src\MigrationTools.Clients.TfsObjectModel\Tools\TfsUserMappingTool.cs:line 175 at MigrationTools.Processors.TfsWorkItemMigrationProcessor.ValidateAllUsersExistOrAreMapped(List1 sourceWorkItems) in D:\a\azure-devops-migration-tools\azure-devops-migration-tools\src\MigrationTools.Clients.TfsObjectModel\Processors\TfsWorkItemMigrationProcessor.cs:line 235
at MigrationTools.Processors.TfsWorkItemMigrationProcessor.InternalExecute() in D:\a\azure-devops-migration-tools\azure-devops-migration-tools\src\MigrationTools.Clients.TfsObjectModel\Processors\TfsWorkItemMigrationProcessor.cs:line 131
at MigrationTools.Processors.Infrastructure.Processor.Execute() in D:\a\azure-devops-migration-tools\azure-devops-migration-tools\src\MigrationTools\Processors\Infrastructure\Processor.cs:line 99
[17:41:49 INF] [16.0.4] TfsWorkItemMigrationProcessor completed in 00:00:00
[17:41:49 ERR] [16.0.4] TfsWorkItemMigrationProcessor The Processor MigrationEngine entered the failed state...stopping run
[17:41:49 INF] [16.0.4] Command ExecuteMigrationCommand completed in "00:11:30.8022547"
[17:41:49 INF] [16.0.4] Check the logs for errors: C:\MigrationTools\logs\20241024173017