Hello @djearthquake, this issue report reads like you're referring to the Steam for Linux client, not a goldsrc game, so I've transferred this issue report to the steam-for-linux issue tracker.
Please copy your system information from Steam (Steam -> Help -> System Information) and put it in a gist, then include a link to the gist in this issue report.
Coming back from suspend makes issue duplicatable.
I've been having this issue lately too. Very easy to trigger: simply set my Steam Chat status to "Offline", so it signs out of Steam Friends, then set the status back to "Online". This loads a completely blank, grey window. I have to restart Steam entirely to get Steam Chat back.
sudo service gdm3 stop then manually started it shows issue is coming form Gnome Desktop Manager when returning from suspend. Going offline, closing friends window by clicking X then exiting Steam prior to suspend seems to remedy this mess. Suspend isn't going to do all that for you and if happens when AFK, as usual, this issue crops up.
There was a new update recently changing a lot of how the system used to work like one can no longer double-click to join server or start Steam with SERVERS. Now it pushes the store without other options. Issue appears to have shifted to the STORE but is a lot easier to recover from. Simply clicking a tab over and back again.
This blank friend list is still super fiddly. I have to change status to something else like invisible or away, disconnect then back to online status; reconnect to stop this blank window frame nonsense.
Nothing extracted yet.
Ever since recent Steam update about a month ago Steam Friends deteriorates and is not viewable. Contents disappear and only show an outline of window frame. Plenty of hard disk space!
This also occurs on OSX. The difference is it corrects itself. Observed when playing Half-Life Opposing Force. Once game is exited the blank/black friends like window appears normal.