The Integration Service captures most exceptions that occur when it calls a COM or Informatica procedure through an External Procedure transformation. For example, if the procedure call creates a divide by zero error, the Integration Service catches the exception.
In a few cases, the Integration Service cannot capture errors generated by procedure calls. Since the Integration Service supports only in-process COM servers, and since all Informatica procedures are stored in shared libraries and DLLs, the code running external procedures exists in the same address space in memory as the Integration Service. Therefore, it is possible for the external procedure code to overwrite the Integration Service memory, causing the Integration Service to stop. If COM or Informatica procedures cause such stops, review the source code for memory access problems.