There is some error log in the Item Number Change utility when I was trying to use it. Apparently, I have to clear the error before I can use it. 

I/C Item Pricing: CDA4409 to CDA4409LG, Error changing number/code! Error Code = 127
I/C Item Pricing Details: CDA4409 to CDA4409LG, Error changing number/code! Error Code = 127
I/C Item Tax Authorities: CDA4409 to CDA4409LG, New record already exists
I/C Location Details: CDA4409 to CDA4409LG, New record already exists
I/C Reorder Quantities: CDA4409 to CDA4409LG, Error changing number/code! Error Code = 127
I/C Reorder Quantities Header: CDA4409 to CDA4409LG, New record already exists
I/C Unit of Measure: CDA4409 to CDA4409LG, Error changing number/code! Error Code = 127
I/C Vendors: CDA4409 to CDA4409LG, New record already exists

Apparently there is one particular item causing the issue, seeking for guide how to solve this.

Thank you.