Access violation Error - Delphi XE2

Hello.

Used -> Delphi Xe2 + RemObjects+SDK+for+Delphi±+8.1.87.1145 + Unidac4.1

Sever -> TROIndyHTTPServer (MomorySession + TROPooledClassFactory)
ServerName -> Midas7RoServer1

Client -> TROWinInetHTTPChannel + TRODataSnapConnection

Error occurs.
When used sometimes ClientDataSet to ApplyUpdates.
Error Msg -> SlrDTd Access violation at address 0072483A in module ‘Midas7ROServer1.exe’. Read of address 00000000
(SlrDTd=ClientDateSet Name)

Midas7Service_Impl.pas

can you launch your server in debug mode and get call stack and see what happened?