Yes a house can be uninsurable especially if the house needs extensive repairs to it.
A house that is in need of major repairs such as a bad foundation, bad basement walls, basement walls caving in, roof needs repaired, house needs paint job, trees too close to the house etc can all make a house uninsurable.
Another thing that can make a house uninsurable is a house that is in a neighborhood that has a high crime rate or a bunch of arson going on.
But as long as the house is in a good neighborhood and is not too severely damaged then you should be able to get insurance on the house.
But if the homeowners insurance company tells you that you need to repair something on the house then you must repair it or you can be dropped from your homeowners insurance.