Transport error - original object cannot be replaced

Hi,

I have created a new transaction code ZXXX for the standard report RFKKBU00 on DEV environment.

Error occured when transporting to Quality : "R3TRTRANZXXX original object cannot be replaced".

SAP proposes the following procedure to fix the problem : "If you still want to import the object, repeat the import with Unconditional Mode 2."

Could anyone tell me what is the cause of the problem and and how to repeat import procedure?

Many thanks,

Ainjaka