How to fix Steam hang freeze lockup when clicking on new gift popup notification
6WARNING - I will NOT be held responsible for any damages the methods shown in this video may cause to yours or someone else's computer, hardware, software, and/or data, including loss of use of such devices and/or loss of data and/or loss of profits from the resulting inability to use such devices and data. Any information or program you choose to put into use from this video is done AT YOUR OWN RISK. As a precaution, I recommend backing up any irrecoverable data before practicing any of the methods shown in this video.
This video will show you how to fix Steam hanging, freezing, and locking-up when clicking on the pop-up notification indicating that you've received a gift. If your Steam client has become non-responsive when you tried to click the popup notification, DO NOT shut down Steam before redeeming said gift, as from experience, you can lose access to said gift (essentially forfeiting it). Instead, by holding the ALT key and pressing the TAB key, switch to your main Steam window to regain control (you can also navigate to steampowered.com using a web browser and login with your Steam credentials). From here, you should have access to your new gift message, which will allow you to accept the new gift by either adding it to your games library or by adding it to your gift inventory.