Duplicate Key issue while Loading BSEG data

Hello Experts,

I was loading and not replicating BSEG data into HANA and it seems that after loading around 100 million record, it went into an error with the below error message in SLG1:

I don't think we can ever have a duplicate record in BSEG table itself for a given combination of Company Code, Accounting Document, Fiscal Year and Item. Then how come we are having this issue in replication.

There is a SLT piece of code which we have, wherein we are performing two things:

a) Loading only 2013 data

b) Defaulting for Invalid/Blank Date Issue as shown below

It would be great, if somebody can throw some light on this.

Thanks & regards,

Jomy