options.contracts array does not take multiple contracts

[Deleted user]

when setting up the store in index.js (as prescribed on https://truffleframework.com/tutorials/getting-started-with-drizzle-and-react) we create an options object with the contracts we want to listen to:

const options = { contracts: [MyStringStore] };
When I try to add multiple contracts in that array, I invariably get the following error:

index.js:1452 uncaught at root at root
at contractsSaga
at takeEvery
at addContract
at instantiateContract
TypeError: Cannot read property 'address' of undefined