some of you may already know that Openmediavault 3.x is in its early testing phase.
BUT be aware - it is still very early beta.
Note, for those of you who already run 3.0, starting with 3.0.14 and above the core code was reworked big time. Expect things to be broken.
Users Thread about downgrading after updating to 3.0.15 (Don't expect Moderator Support on this issue; Don't ask for when Plugin XY will be updated): [HOWTO] Downgrade to version 3.0.13 after accidentally upgrading to newer version (breaking things)
So if you don´t know how to build your own packages via sourceforge and install SVN versions,
please stay away from it till an official announcement from @votdev will be posted.
Any posts regarding OMV 3.x that point to an error will be closed without warning.
If you install OMV 3.x though, you are on your own! You won´t get any support until it is declared as stable!
Do not use omv-release-upgrade to upgrade your OMV 2.x to 3.x. It may damage your installation completely at the moment!
If you still want to try it and absolutely know what you are doing, feel free to report any bugs to http://bugtracker.openmediavault.org/ or https://github.com/OpenMediaVault-Plugin-Developers if its for a third party plugin.
Updated 2016/04/06: Added note about 3.0.14 and above; added link to github for third party plugins
Updated 2016/04/24: Added note to downgrade Thread.