How are distresses properties insured

[Moises B.]

Running into a slight snag.  Buying a SBO property, and clear to close (right now trying to coordinate dates).  The insurance company now sends me a correspondence (after first already providing me a policy #) indicating they cannot insure me due to slight modifications needed on the property.  So while I can probably close, considering the insurance doesn't expire a month from today, I'm certain I'll run into the same issue with the other insurer.

Here's my question: Should this fall under the seller to fix or provide me with funds to fix or is it now my problem, because I should've caught it during my walk through (I had a contractor inspect, but apparently he missed it).  The fix is outside shingles missing, and the front door "rotting" and paint peeling (it seemed fine to me honestly), but if they're claiming those two things preclude insurance, then most of this area is not insured...(being facetious).

This begs another question.  What happens when you buy a property that needs significant rehab, say 40K worth??? As I'm currently under contract with...from what I understand the bank requires insurance for you to close is this a true statement?

Any help is appreciated.