voiding a contract

Well, you’re probably not going to like the answer, but it is ‘maybe.’  Leases, particularly equipment leases can be tricky – especially when it comes to the fine print (or boilerplate).  That said, it sounds like you may just have a way out of the contract.  In my experience, equipment leases get tricky because the leasing folks don’t really care whether it still does what you need it to do; however, it does matter when the equipment is no longer compliant to even do the standard job for which it was built.  And you may even have other provisions that work in your favor.  Be careful, though – even if you have a strong legal defense to a breach of contract action, if you just stop paying, they’re likely to sue you to recover the equipment AND potentially for economic loss on the contract.  Also, be aware of whether or not you are personally liable on the contract.  These things can get into some big bucks for breach suits.  I would highly suggest sitting down with an attorney to review the contract in detail and perhaps even hire the attorney to help you negotiate your way out (and maybe even litigate if necessary.)  Best of luck.