Translation Manager fails to send items for translation and the following error stack is being recorded by the TranslationManager.log file.

Note: The Translation Manager and Content Manager databases are Microsoft SQL databases hosted on Azure, not Azure databases.

Communication with the underlying transaction manager has failed.

at System.Transactions.TransactionInterop.GetOletxTransactionFromTransmitterPropigationToken(Byte[] propagationToken)
at System.Transactions.TransactionStatePSPEOperation.PSPEPromote(InternalTransaction tx)
at System.Transactions.TransactionStateDelegatedBase.EnterState(InternalTransaction tx)
at System.Transactions.EnlistableStates.Promote(InternalTransaction tx)
at System.Transactions.Transaction.Promote()
at System.Transactions.TransactionInterop.ConvertToOletxTransaction(Transaction transaction)
at System.Transactions.TransactionInterop.GetExportCookie(Transaction transaction, Byte[] whereabouts)
at System.Data.SqlClient.SqlInternalConnection.GetTransactionCookie(Transaction transaction, Byte[] whereAbouts)
at System.Data.SqlClient.SqlInternalConnection.EnlistNonNull(Transaction tx)
at System.Data.SqlClient.SqlInternalConnection.Enlist(Transaction tx)
at System.Data.ProviderBase.DbConnectionInternal.ActivateConnection(Transaction transaction)
at System.Data.ProviderBase.DbConnectionPool.PrepareConnection(DbConnection owningObject, DbConnectionInternal obj, Transaction transaction)
at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal& connection)
at System.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal& connection)
at System.Data.ProviderBase.DbConnectionFactory.TryGetConnection(DbConnection owningConnection, TaskCompletionSource`1 retry, DbConnectionOptions userOptions, DbConnectionInternal oldConnection, DbConnectionInternal& connection)
at System.Data.ProviderBase.DbConnectionInternal.TryOpenConnectionInternal(DbConnection outerConnection, DbConnectionFactory connectionFactory, TaskCompletionSource`1 retry, DbConnectionOptions userOptions)
at System.Data.SqlClient.SqlConnection.TryOpenInner(TaskCompletionSource`1 retry)
at System.Data.SqlClient.SqlConnection.TryOpen(TaskCompletionSource`1 retry)
at System.Data.SqlClient.SqlConnection.Open()
at Tridion.ContentManager.Data.AdoNet.DatabaseUtilities.GetConnection()
at Tridion.ContentManager.Data.AdoNet.DatabaseUtilities.ExecuteNonQuery(StoredProcedureInvocation storedProcedureInvocation, FieldDictionary& dataFields)
at Tridion.ContentManager.Data.AdoNet.DatabaseUtilities.ExecuteNonQuery(StoredProcedureInvocation storedProcedureInvocation)
at Tridion.ContentManager.Data.AdoNet.IdentifiableObjectDataMapper.Tridion.ContentManager.Data.IIdentifiableObjectDataMapper.IsExistingObject(TcmUri id)
at Tridion.ContentManager.Session.IsExistingObject(String uri)
at Tridion.TranslationManager.DomainModel.CoreServiceProxy.CallWithErrorHandling[T](Func`1 callMethod, String traceFormatString, Object[] traceParameters)
at Tridion.TranslationManager.DomainModel.TranslationInfoAppdataStorage.TcmUriTranslationInfoAppdataStorage.ResolveTcmUriForAppdataStorage(TcmUri uri)
at Tridion.TranslationManager.DomainModel.TcmItemTranslationInfo..ctor(ITranslationInfoAppdataStorage storage, IDictionary`2 preloadedItems, IDictionary`2 preloadedAppDataDocuments, UserContext userContext)
at Tridion.TranslationManager.DomainModel.Service.SendForTranslationTask.<>c__DisplayClass11_0.<InternalFinalizeTmsJob>b__33(<>f__AnonymousType41`2 <>h__TransparentIdentifier2)
at System.Linq.Enumerable.<>c__DisplayClass7_0`3.<CombineSelectors>b__0(TSource x)
at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
at Tridion.TranslationManager.DomainModel.Service.SendForTranslationTask.<>c__DisplayClass11_0.<InternalFinalizeTmsJob>b__0(TransactionScope scope)
at Tridion.TranslationManager.DomainModel.TmSession.<>c__DisplayClass129_0.<ExecuteInTransactionScope>b__0(TransactionScope scope)
at Tridion.TranslationManager.DomainModel.TmSession.ExecuteInTransactionScope[T](TransactionScopeOption scopeOptions, TransactionOptions transactionOptions, Func`2 func)
at Tridion.TranslationManager.DomainModel.TmSession.ExecuteInTransactionScope(TransactionScopeOption scopeOptions, TransactionOptions transactionOptions, Action`1 action)
at Tridion.TranslationManager.DomainModel.TmSession.ExecuteInTransactionScope(TransactionScopeOption scopeOptions, Action`1 action)
at Tridion.TranslationManager.DomainModel.Service.SendForTranslationTask.InternalFinalizeTmsJob(TranslationJob job, TranslationSystemJobRequest jobRequest, IEnumerable`1 itemRequests, HashSet`1 uploadedLanguageIds, IEnumerable`1 targetItems)
at Tridion.TranslationManager.DomainModel.Service.SendForTranslationTask.FinalizeTmsJob(TranslationJob job, TranslationSystemJobRequest jobRequest, IEnumerable`1 itemRequests, IEnumerable`1 targetItems)
at Tridion.TranslationManager.DomainModel.Service.SendForTranslationTask.ProcessClient(TranslationJob job, String clientId, List`1 resolvedItems)
at Tridion.TranslationManager.DomainModel.Service.SendForTranslationTask.Process()
at Tridion.TranslationManager.DomainModel.Service.ServiceTask.ThreadMethod()


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The MSDTC transaction manager was unable to pull the transaction from the source transaction manager due to communication problems.
 Possible causes are: a firewall is present and it doesn't have an exception for the MSDTC process, the two machines cannot find each other by their NetBIOS names, or the support for network transactions is not enabled for one of the two transaction managers. 
(Exception from HRESULT: 0x8004D02B)

at System.Transactions.Oletx.IDtcProxyShimFactory.ReceiveTransaction(UInt32 propgationTokenSize, Byte[] propgationToken, IntPtr managedIdentifier, Guid& transactionIdentifier, OletxTransactionIsolationLevel& isolationLevel, ITransactionShim& transactionShim)
at System.Transactions.TransactionInterop.GetOletxTransactionFromTransmitterPropigationToken(Byte[] propagationToken)

Resolution: Ensure to open the appropriate MSDTC port allowing connection between the Tridion Content Manager server and the Microsoft SQL instance.