PG - 9.5.4 EDB DataObjects - 5.0.9

Xtensive.Orm.StorageException: SQL error occured.
SQL error details 'Type: Unknown;'
Query 'SET CONSTRAINTS ALL IMMEDIATE;'
Original message 'ERROR: 25P02: current transaction is aborted, commands ignored until end of transaction block' ---> Npgsql.NpgsqlException: ERROR: 25P02: current transaction is aborted, commands ignored until end of transaction block
   в Npgsql.NpgsqlState.<ProcessBackendResponses_Ver_3>d__a.MoveNext()
   в Npgsql.ForwardsOnlyDataReader.GetNextResponseObject()
   в Npgsql.ForwardsOnlyDataReader.GetNextRowDescription()
   в Npgsql.ForwardsOnlyDataReader.NextResult()
   в Npgsql.ForwardsOnlyDataReader..ctor(IEnumerable`1 dataEnumeration, CommandBehavior behavior, NpgsqlCommand command, NotificationThreadBlock threadBlock, Boolean synchOnReadError)
   в Npgsql.NpgsqlCommand.GetReader(CommandBehavior cb)
   в Npgsql.NpgsqlCommand.ExecuteNonQuery()
   в Xtensive.Orm.Providers.StorageDriver.<ExecuteNonQuery>b__d(DbCommand c)
   в Xtensive.Orm.Providers.StorageDriver.ExecuteCommand[TResult](Session session, DbCommand command, Func`2 action)
   ---  ---
   в Xtensive.Orm.Providers.StorageDriver.ExecuteCommand[TResult](Session session, DbCommand command, Func`2 action)
   в Xtensive.Orm.Providers.StorageDriver.ExecuteNonQuery(Session session, DbCommand command)
   в Xtensive.Orm.Providers.SqlExecutor.ExecuteManyBatched(IEnumerable`1 statements)
   в Xtensive.Orm.Providers.SqlExecutor.ExecuteMany(IEnumerable`1 statements)
   в Xtensive.Orm.Upgrade.SchemaUpgrader.ExecuteTransactionally(IEnumerable`1 batch)
   в Xtensive.Orm.Upgrade.UpgradeActionSequence.ProcessWith(Action`1 regularProcessor, Action`1 nonTransactionalProcessor)
   в Xtensive.Orm.Upgrade.SchemaUpgrader.UpgradeSchema(SchemaExtractionResult extractedSchema, StorageModel sourceModel, StorageModel targetModel, ActionSequence upgradeActions)
   в Xtensive.Orm.Upgrade.UpgradingDomainBuilder.SynchronizeSchema(Domain domain, SchemaUpgrader upgrader, SchemaExtractor extractor, SchemaUpgradeMode schemaUpgradeMode)
   в Xtensive.Orm.Upgrade.UpgradingDomainBuilder.PerformUpgrade(Domain domain, UpgradeStage stage)
   в Xtensive.Orm.Upgrade.UpgradingDomainBuilder.BuildMultistageDomain()
   в Xtensive.Orm.Upgrade.UpgradingDomainBuilder.Run()
   в Xtensive.Orm.Upgrade.UpgradingDomainBuilder.Build(DomainConfiguration configuration)
   в Xtensive.Orm.Domain.Build(DomainConfiguration configuration)

Contents of orm.sql.log:

2016-08-29 14:12:04.3482 | Info | Xtensive.Orm.Sql |     Session 'System, #14'. Schema upgrade script:
SET CONSTRAINTS ALL IMMEDIATE;

CREATE TABLE "public"."Metadata.Assembly" ("Name" character varying(1024) NOT NULL,
"Version" character varying(64),
CONSTRAINT "PK_Assembly" PRIMARY KEY ("Name")) WITHOUT OIDS;

CREATE TABLE "public"."Metadata.Type" ("Id" integer NOT NULL,
"Name" character varying(1000),
CONSTRAINT "PK_Type" PRIMARY KEY ("Id")) WITHOUT OIDS;

CREATE TABLE "public"."Metadata.Extension" ("Name" character varying(1024) NOT NULL,
"Text" text,
"Data" bytea,
CONSTRAINT "PK_Extension" PRIMARY KEY ("Name")) WITHOUT OIDS;

CREATE TABLE ......
......
......

SET CONSTRAINTS ALL DEFERRED; 
2016-08-29 14:12:04.3482 | Info | Xtensive.Orm.Sql |     Session 'System, #14'. SQL batch: 
SET CONSTRAINTS ALL IMMEDIATE;
2016-08-29 14:12:04.3522 | Info | Xtensive.Orm.Sql | Session 'Default, #15'. Creating connection.