Unwanted Delimiters in EDI segments

Thanks for the quick response Manohar. No I am not supplying a sub-field delimiter. Here is how my data appears,
ISA00 * ZZE725 EZ25003015544774480898201315U0040100000000011P~:GSFAE725 E7250035544774482003062513150000000001X004010~ ST9978383~AK1IN21~AK28500219~AK5A~AK28100220~AK5A~
AK2
8100221~
AK5
A~
AK28100222~
AK5A~
AK2
8100223~
AK5
A~
AK28100224~
AK5A~
AK2
8100225~
AK5
A~
AK28100226~
AK5A~
AK2
8100227~
AK5
A~
AK28100228~
AK5A~
AK2
8100229~
AK5
A~
AK28100230~
AK5A~
AK2
8100231~
AK5
A~
AK28100232~
AK5A~
AK2
8100233~
AK5
A~
AK9A151515~
SE348383~

1P~:GS… doesn’t look right.

It should be …1P*:~GS…

How is the ISA being created?

You need to fill your sub-field delimiter also when you call your convertToString service and in your case, it looks like it is ‘:’ generated by system. As Rob pointed out, your ISA seems to be wrong.
The last 3 characters in your ISA just before ‘GS’ represents the delimiters field, subfield and segment respectively. These are mandatory.

FYI

IS 601 Fix17 fixes Unwanted Delimiters in EDI segments.