Cann`t deploy contract using pragma solidity 4.21 (after solidity 4.20)

Question

I cant call me a pro at all. Rather newbie than pro, wishing to learn and develop. I`m sincerely asking you to help me.

I have the token and crowdsale contract (testing) which I deploy and initialize using solidity ^0.4.20 without any issues. But in the REMIX I have an exclamation mark there like this:

Warning: Function state mutability can be restricted to pure function finalization() internal { ^ Spanning multiple lines.

No matter of what it still works fine (include finalization step).

But when I try to compile it with solidity ^0.4.21

(after adding emit and some changes in ...............(this.balance); to ...........(myAddress.balance); with adding additional string above: address myAddress = this;) - to remove all exclamation marks (except finalization())

Token deploys fine but the crowdsale contract gives me an error:

"Error: gas required exceeds allowance or always failing transaction"

Seems that its not enought just to make this changes (above). Did I miss anything?. + Could this finalization() warning exclamation mark affect and breake everything in 4.21?

I saw people help each other here and it works very effective. So I decided to post my question as well.

Thank you in advance.

Answer 1

You should use address(this).balance to cast this to the address type instead of adding one more variable.

Maybe this will help, if no - provide the full source of your contract please.