PostgreSQL: "Unexpected server response : ¹."

The question is how can I avoid this exception?

UniDAC 10.1.0 with PosgreSQL server.

I try to return a blob field of PosgreSQL type bytea using this code

with TUniQuery.Create(nil) do
try
    Connection := ucDL;
    SQL.Add('SELECT ' + FieldN + ' FROM ' + sNumeTabelComenzi + ' WHERE CodUnic=' + IntToStr(CodUnic));
    Active := True; //Unexpected server response

And this is the call stack:

exception class    : EUniError
exception message  : Unexpected server response : ¹.

main thread ($3378):
00a390db +027 WinArhi_15.exe Uni                       HandleInternalError
00a3dde3 +03b WinArhi_15.exe Uni                       TCustomUniDataSet.OpenCursor
77028db1 +021 ntdll.dll                                KiUserExceptionDispatcher
003a843c +380 WinArhi_15.exe madExcept                 IsValidObject2
003e15f3 +0bb WinArhi_15.exe madExcept                 SetLastExceptionHelper
003e165a +05a WinArhi_15.exe madExcept                 MyRaiseExceptProc
0101fc0e +0c2 WinArhi_15.exe PgClassesUni              TPgSQLConnection.ProcessInternalException
0102ae2e +042 WinArhi_15.exe PgClassesUni              TPgSQLRecordSet.ProcessFetchedException
00a17add +321 WinArhi_15.exe CRAccess                  TCRRecordSet.InternalFetch
77028db1 +021 ntdll.dll                                KiUserExceptionDispatcher
003a843c +380 WinArhi_15.exe madExcept                 IsValidObject2
003e15f3 +0bb WinArhi_15.exe madExcept                 SetLastExceptionHelper
003e165a +05a WinArhi_15.exe madExcept                 MyRaiseExceptProc
00fd988e +002 WinArhi_15.exe PgSQLProtocolUni          TPgSQLProtocol.RaiseError
00fd98ad +019 WinArhi_15.exe PgSQLProtocolUni          TPgSQLProtocol.RaiseError
00fd95a6 +276 WinArhi_15.exe PgSQLProtocolUni          TPgSQLProtocol.ProcessMessage
00fdc830 +120 WinArhi_15.exe PgSQLProtocolUni          TPgSQLProtocol30.ProcessMessage
00fd96b1 +0b5 WinArhi_15.exe PgSQLProtocolUni          TPgSQLProtocol.ProcessMessageQueue
00fd8130 +0c8 WinArhi_15.exe PgSQLProtocolUni          TPgSQLProtocol.FetchStmt
00fdc384 +01c WinArhi_15.exe PgSQLProtocolUni          TPgSQLProtocol30.FetchStmt
0102a967 +057 WinArhi_15.exe PgClassesUni              TPgSQLRecordSet.FetchBlock
00a17979 +1bd WinArhi_15.exe CRAccess                  TCRRecordSet.InternalFetch
00a17c7a +17e WinArhi_15.exe CRAccess                  TCRRecordSet.Fetch
0102814d +059 WinArhi_15.exe PgClassesUni              TPgSQLRecordSet.FetchAll
00a176e3 +0bf WinArhi_15.exe CRAccess                  TCRRecordSet.ExecFetch
01028099 +081 WinArhi_15.exe PgClassesUni              TPgSQLRecordSet.ExecFetch
00a14d59 +175 WinArhi_15.exe CRAccess                  TCRRecordSet.InternalOpen
0102a5e7 +01b WinArhi_15.exe PgClassesUni              TPgSQLRecordSet.InternalOpen
0092cadc +034 WinArhi_15.exe MemData                   TData.Open
009a4dc8 +02c WinArhi_15.exe MemDS                     TMemDataSet.InternalOpen
009e02e3 +117 WinArhi_15.exe DBAccess                  TCustomDADataSet.InternalOpen
004dbdba +00e WinArhi_15.exe Data.DB                   TDataSet.DoInternalOpen
004dbe6a +016 WinArhi_15.exe Data.DB                   TDataSet.OpenCursor
009a51ea +00a WinArhi_15.exe MemDS                     TMemDataSet.OpenCursor
009d9785 +201 WinArhi_15.exe DBAccess                  TCustomDADataSet.OpenCursor
00a3ddcf +027 WinArhi_15.exe Uni                       TCustomUniDataSet.OpenCursor
004dbd1d +055 WinArhi_15.exe Data.DB                   TDataSet.SetActive
009d9573 +033 WinArhi_15.exe DBAccess                  TCustomDADataSet.SetActive
0141e90c +0b0 WinArhi_15.exe ModulDateLocale  6226  +6 TDateLoc.SalveazaInStreamCampDinComanda