HSN wise summary in table 12

hello we are a mumbai based service provider to corporates, we are a normal tax payer and our turnover is less than 1.5 cr. 

While filing gstr1 and clicking the submit button we are getting following msg: No records found in Table 12. Add records in Table-12 corresponding to details saved in tables: B2B .

Do we need to fill details in the table 12? Is it mandatory? Or we can go ahead with submission and filing.