EH generation

Dear EM experts

The BAPI /SAPTRX/BAPI_EH_ADDEVENTMSG_02 has an Option EH_GENERATION_MODE. The documentation says, the Option A has an effect that all Messages generate an EH without customizing check. When I run the BAPI, I get the error "no active Event handler found", but the message Details are updated in EVM_HDR. Would it be an Option to put A into the EH_GENERATION_MODE to resolve this issue? and if so, what is the function module that I have to fill into field EH_GENERATION_FUNCTION.

Any other other tips how I can get the message tobe processed and put into the execution tab of the freight unit?

Thanks in advance

Petra