According to my experience this meesage could be misleading. If the error is caused by the 'Agree' indicator for Fund you should get AAPO190 with the mentioned text. If AAPO189 comes up with the same text as AAPO190 (error for Fund), most likely it is caused by the 'Agree' indicator for Funds Center. This is because your FMDERIVE probably derives Fund from the Funds Center. So, go ahead and remove the 'Agree' indicator for funds Center and test it again.
You might want to give it some thoughts in terms of what that means to your organization if the asset aquisition postings have different FM account assignment than that of asset master. It was not an acceptable practice for my business owner.