Hi Jay,
The field ARG_STRING has data type STRING with length 0 (i.e. no length restriction). The documentation says the following:
The types RAWSTRING and STRING for LOB s have a variable length. A maximum length can be specified, but there is no upper limit. The maximum length is an actual length that cannot be exceeded. The maximum length is used for optimizations when storing string fields in the database.
If the field does not contain any relevant information, then I suggest to follow Raf's advice: skip the field either by excluding it in the DataSource or removing it in the view.
If the field contains relevant information, then I suggest to build a Function Module based Extractor. You should define a field in the Extract Structure with a data type and length which is not problematic for BW. In the coding you have to take care of the assignment of the STRING field to the "BW compatible" field.
Best regards,
Sander