All future maps are required to use only the new 1.24 core functions. Because a lot of the DotA code was deep rooted on the old functions, this required that most of the code be rewritten. I've been working on this for well over a month, however because 1.24 itself is bugged, we need to wait for 1.24b for the new functions to work properly.
As soon as 1.24b is released, I will release 6.62. Again 6.62's only focus is on the massive code update. Because of the nature of this patch and all of the new code, I recommend that tournaments wait a few days at the very least before using 6.62.
To clarify, 6.61c is not really "compatible" with 1.24, it is only running in virtual mode, something that is not sustainable for actual content updates. That is why it was important to migrate to native code, so future updates are possible.