It doesn't matter, from a legal persective, whether the business can afford the rent or not: it--or you; see below--are  still obligated to the lease. If  the lease gives you a grace period, you are entitled to it: you are  entitled to whatever rights the lease gives  you, but no others.A light that is out would almost certainly not affect your obligations: only factors that render the premises unfit for their intended purpose would affect the tenant's obligations, and a light that's out almost certainly does not rise to that level.If the business is a corporation ("inc.") or limited liability company ("LLC") and the business, not you, is the tenant and you signed the lease only in your capacity as a managing member or officer of the company, then--as long as  you did not also give a personal guaranty--only the business is liable under the lease. One option is to simply shut the business down in that case.However, if the business was a sole proprietorship, or you signed the lease in your personal capacity, or you gave the landlord a personal guaranty, then you could be held personally liable for all the rent due under the lease.