Customer LTSD Issue failing for certain countries

[Dhanesh_Mohan]

Team,

We implemented the Preference Processing module to be specific the Outbound customer C-LTSD's. We are facing an issue with issuing the LTSD's for two countries SouthKorea(KR) and Serbia. Any LTSD's for Invoices belonging to these two countries, the system is failing to issue the C-LTSD's. We noticed that when creating billing document for Customers from these two countries in the feeder system, the same is not transferring to GTS. In SLG1 we can see the transfer failing with the error - 'Legal Regulation is not Unique'. Message no. /SAPSLL/API_INBOUND060. Diagnosis details of the message says "The legal regulation cannot be determined uniquely for country key DK. Multiple legal regulations are active for country key DK and service of type Customs Processing". However manually transferring the document again via GTS cockpit (/SAPSLL/SD0C_RIMAR3) will transfer the billing document to GTS system and the same is visible in table ‘/SAPSLL/PREBDOC’, my understanding is this is the table from where the billing docs are picked for issuing the LTSD's. But ultimately when issuing the C-LTSD (Tcode - /SAPSLL/LTSDOUT_1) the program fails to issue ..its says '0 LTSDs were created', also the corresponding entry gets deleted from the table ‘/SAPSLL/PREBDOC’. This is a very strange behaviour. Please note that the issue is only faced with Invoices for only countries south Korea and Serbia, rest all countries the system is working as expected. Attached a snapshot of the error in Billing doc transfer. 

Any pointers to solve this issue is highly appreciated. Please note I already  check where there are any multiple country assignments for the Legal Regulations, but did not find any, so that cause can be ruled out. 

Thanks,

Dhan