Hi Manohar,
This issue occurs because system compares validity end date of classification assignment with the validity of numbers in table /SAPSLL/CTSNUM. If it doesn't find any valid records in this table with end date 31.12.9999, it throws this error.
Apparently the only way to fix this issue is to change 'valid to' date of numbers to 31.12.9999 unless SAP fixes the code (comparison logic).
Is there any other way to change 'valid to' date in table /SAPSLL/CTSNUM in bulk apart from creating a program to update this table field directly?
regards,
Kul Vaibhav