The WordPress Support Forum and WordPress Codex only provide support and documentation for officially released versions of WordPress, as downloaded from http://wordpress.org/download/ and only from http://wordpress.org/download/.
The current officially supported version is WordPress 4.0.1.
If you use an un-released version of WordPress and experience trouble, your only official support option is the WordPress testers mailing list. If you are unable or unwilling to file bug reports, and help fix problems, please do not use anything other than the officially released versions.
Some folks in the WordPress IRC channel might be familiar with unreleased versions, but it'll be hit-or-miss, and no guarantee of support is provided.