Problem

-- getting this error when simulating a flow in Mapping Services

Log error while opening
....\DataProcessingLog.txt> could not be read.

Resolution

* open the Run -> Run Configurations -> DML Simulations -> <the simulatino object that failed>

* open the "Attributes" tab and look for an attribute of type "Record"

* if such type of attribute is present, remove it

* try the simulation

* if it still fails, remove all attributes except the default ones : ACCEPT_INPUT_DOCUMENTS_WITH_ERRORS and ACCEPT_OUTPUT_DOCUMENTS_WITH_ERRORS

* try the simulation