Nil gstr-3b

The GSTR-3B for Oct. 2017 was submitted on 19th Dec. 2017 with Nil Supply and Nil ITC.  But while filling it (with EVC), that retuned with the message – “Please clear the pending liability first and then proceed for filling”. As suggested by the GST Helpdesk adviser we deposited the challan for late fee for 30 days - Rs. 600/-. But still we are not able to file the return. Please provide the solution.