We have a customer that has the following verbiage in their contract; To the fullest extent permitted by law, subcontractor for itself and for its subcontractors, laborers, etc. and all others directly or indirectly acting for, through or under it any of them covenants and agrees that no liens or claims, whether a mechanics lien or an attested account or otherwise, will be filed or maintained against the Project or Premises or any part thereof or any interests therein or any improvements thereon, or against any monies due or to become due from the owner to contractor or from contractor to the subcontractor etc. Does this mean we are not able to file a lien if we are not getting paid?
You have the ability to record a lien if necessary. This contract clause would not be enforceable to prevent you (or anyone else) from recording a mechanics lien.
The Nevada Supreme Court has found contract provisions that try to prohibit contractors from filing mechanic's liens on Properties are unenforceable. Thus, if this provision is in your contract, they cannot enforce it. However, you need make sure to follow all prerequisites under NRS 108 to make sure there are no other means to try to invalidate your lien rights.
I would suggest you meet with a construction attorney to work through this as well, to make sure.