In my case, this was caused because I copy the project from another macbook, and somehow it brought together some certificates, and building the project xcode was crashing with this error, so I clone the project again from the git, and all works fine.

The new api is already ready, and returns the new model all changed, my concern is to take the path of changing the structure of recording and reading of the coredata, and it is an impossible job to complete, changing the names of the fields everywhere , this counting that I can only test it at the end, which can be complicated later to correct all the errors.

the json is : { "Return": { "Summary": { "AvailableBalanceTotal": 1791381.19, "CurrentBalanceTotal": 0 }, "Accounts": [ { "AccountType": "D", "AccountNumber": "17228676", "AccountDescription": "Corporate Checking Foreign", "AccountProductCode": "56", "AvailableBalance": 1791381.19, "CurrentBalance": 0, "HoldAmount": 0 } ] }, "Success": true }