Cannot Update to 0.58 Through Steam

[HateDread 13]

Hey all,

Arma 3 Alpha says 'Update required'. I hit play, it comes up with the 'Updating Arma 3 Alpha' window - it says 'Preparing to launch ArmA 3 Alpha...' above the empty update bar. This hangs for a minute, then I get;

'An error occured while updating Arma 3 Alpha (connection time out)'.

Steam connects and updates other games, so Steam IS connected.

I've deleted Appcache folder and restarted PC, then Steam, and it made no change, nor did deleting ClientRegistry.blob and restarting Steam.

This happens in both the normal and development streams.

Any ideas?

- HateDread.