Buyers can't get financing due to zoning

[Brad Birky]

We are in the process of trying to sell our duplex in Toledo and have run into (yet another) issue. The buyers have reported that they are unable to obtain financing since the duplex (built in 1907) is located in an area that is zoned for single family homes (Toledo zoning was established much later). The issue the banks reportedly have is that IF the property needs to be rebuilt at some point that it would have to be rebuilt as a single-family unit instead of multi-family. 

The real kick in the pants is that EVEN IF the doomsday scenario occurred, since the price point is so low the property would still cash flow as a SFR - but the underwriters don't want to hear that. We know we could apply for a zoning change, but that process could/would take months and we are beyond ready to move onto our next investment.

Has anyone else come across problems like this, where the lender is going down a rabbit hole and denying funds because of something that could possibly happen in the future?