...
This expression contains two iif(logexpr, result_if_true, result_if_false) conditions:
1. iif(StringLength(\5C3Aparam_TASK_genericload_unpacker_DataFlowFiles\5C3A)=0 – This one checks the DataFlowFiles OutParam (a default variable for Task Unpacker, where it writes all unzipped file names). If this variable equals 0 (there were no files in the archive), the workflow step is skipped.
If it is not zero, the second condition activates:
2. iif(Find(\5C3Aparam_TASK_genericload_unpacker_DataFlowFiles\5C3A, 'ISSUER')!=-1 – This condition checks this variable on containing files matching 'ISSUER' file mask and if such are missing, the step is skipped.