An update has been released for the Steam Client and will be automatically downloaded. 
This update is a small set of fixes to the client released earlier this week.  It includes the following new fixes.
General- Fixed some large SteamWorkshop mods causing some users to run out of memory and crash on update
 
- Fixed and simplified PayPal purchase path in Big Picture mode
 
- Steamworks: Fixed timeouts uploading leaderboard scores for games that update scores very frequently
 
Windows- Fixed regression with AppOverlay.dll causing compatibility issues with some applications
 
The following changes from the prior update will also be new if you have not already updated recently.
General- Added support for regional EULAs 
 
- Improved caching of leaderboard API requests
 
- Improved handling of warnings on unrecognized links in chat 
 
- Fixed bug causing Windows service log message "Error: Failed to poke open firewall" 
 
- Fixed installing games from older retail discs
 
- Fix message shown when you unblock someone 
 
- Improved keyboard accessibility in block/unblock success dialog
 
- Fixed removing empty sub folders after game updates
 
- Fixed SteamGuard UI problem preventing login in rare configurations 
 
- Fixed launching games dialog getting stuck in "Preparing to launch..." state
 
- Fixed installed apps detecting content updates
 
- Fixed inability to install games or force updates outside of the auto-update time window, if specified 
 
- Fixed repeated attempts to apply pending updates to a game that is currently running
 
Windows- Improved Steam overlay compatibility with 64-bit games, especially under Windows 8.1 
 
- Fixed a hang that occurred when opening the overlay for the second time in some games
 
Mac OS X- Improved initial startup time when launching Steam
 
- Fixed crash in some newer games when launched from Steam
 
Linux + SteamOS- Updated the steam-runtime for Ubuntu 14.04 compatibility
 
- Fixed potential hang when using certain UI toolkits that relied on SIGCHLD
 
- Fixed a game crash occurring when more than ten processes were attached to the Steam overlay, fixing "CID The Dummy" on Linux
 
- Added support for setting voice input device in Big Picture
 
Big Picture- Load correct localized eula if the language changes in the Choose Language panel
 
- Fix progress % displayed for items that are queued for download
 
- Fixed a bug in Web browser where big pages would be erroneously clamped
 
- Fixed UI for pre-loading games
 
- Added login help support for forgotten password and account name
 
Virtual Reality Mode- Added Virtual Reality mode to the View menu and removed the vr command line option. This will only appear if SteamVR is installed and if a supported HMD is detected
 
- Added support for switching from desktop mode to VR, then back to desktop and into Big Picture
 
- Added support for detecting when an HMD has been plugged in after Steam has started
 
- When running in VR mode Steam will now open only the VR window and not the normal Big Picture window
 
- Moved VR mode log files under the Steam client install directory