EHS data upload from Content providers through EHS OCC

Hi,

Can anyone help me with this error which i'm getting when i try to upload data for a particular regulation TDG from EHS OCC,

" There is already data in the valuassignment for TDG". but when i checked that , there is no data , i had checked that while uploading in EHS OCC where there will be two windows displaying data from content provider and EHS.