Importing BOM lines Issue

Hi Everyone,

We have Bill of materials form in this lines button opened Bom Lines form → in this overview Tab and dimensions tabs are there, but in this dimensions tab 3 fileds colour,size, configuration ,this three fields added beside item number in overview tab also, actually this BOM lines data i have in excel sheet ,but i already imported that data to bom lines form but error came.

that error is dimension number is already exist . actually this dimension no filed is in inventdim table field.

how to solve this error?

can u tell me this solution?