If you are not able to generate e-waybill suddenly even it was working fine earlier,possible reasons may be as given below
1.Check the GSP credentials entred in BUSY under GST/VAT tab for generating e-waybill automatically in BUSY
2.Validate GSP credentials in BUSY
3.Check by loggin into portal,is it loggin in or not
4.Create json file for e-waybill of invoice and uplaod manually on e-waybill portal,if still not generating e-waybill,it may be server issue
5.Switch GSP id from webtel to pinnacle or vice versa if there is server issue