We put a lien on a project and the sub is still not paying. What is next?
Next step: You should retain a construction attorney to evaluate your legal situation and to provide advice. If your mechanic's lien is invalid, you may have violated the Texas Fraudulent Lien Act, and could be liable for statutory damages of $10,000, or actual damages, whichever is greater, plus attorney's fees.
It appears that you may be a supplier to a subcontractor or have some other contractual relationship with a subcontractor. Filing a lien does not obligate a subcontractor to pay, it could induce the owner or original contractor (often the general contractor) to pay.
Good luck.