Selling Challange

Hello Guys - Need some help on the challenge of selling my first rehabbed property :

I rehabbed my first property. The problem i had is that my GC hired a foundation company which is not reputable and did not do the foundation work with an engineering evaluation. so i don't have the scope of work done on the foundation. The house is rehabbed really nice and the buyers have no issues with the rehab. however most interested buyer ask about the engineering evaluation report which i cannot produce, Hence i am having difficulty selling the property. 

Any advice would be really appreciated