There are a number of issues here so I'll try to address them all: 1) yes a lender can ask that a lienor sign a subordination agreement; 2) yes the subordination agreement would be enforceable with regards to the lienor; 3) no you cannot force the lienor to sign the subordination agreement; 4) no you cannot force the lender to accept a subordination agreement; and 5) it is very unlikely any party would agree to the subordination agreement. Typically when the lien is disputed the best way to remove it and push the refinance forward is to obtain a lien discharge bond. But if the lien is on the building and not the unit you may not be in a position to obtain the lien discharge bond.
The information provided herein is for informational purposes only and does not constitute legal advice. No attorney-client relationship is created by this answer. You should consult with a local attorney regarding your specific situation to obtain legal advice.