As said before, this check is not very helpful because quite a view things could raise an `Exception` in `DifferentialEvolutionSolver` call, not just the one you're trying to catch (which does not have a specific type, so is difficult to catch unless you also check the error message).

Anyways, you can probably remove this check. I guess if the user passes a string instead of a numeric value, they shouldn't be surprised to get some exception.