If you haven’t already I recommend creating using tests for your crowdsale to appropriately test your contract. You should check your rate and minimum and maximum buy amounts to check your validation. Also, your crowdsale appears as though it should be holding tokens to sell, so ensure that it has enough tokens to fulfill the purchase.
You can have a look at Simple ERC20 Crowdsale for an example of unit tests.
As an aside, please Format code in the forum.