many users including us noticed a problem with Steam Guard code textbox not getting visible when it should. I noticed that myself while trying to chat with a friend. After doing some debugging at home, thinking first there was a bug in the app I realised that something must have changed with the login API of the Steam API. In fact there is no bug with the app. The Steam Guard code cannot be entered since the app awaits from Steam API a specific response like “please enter Steam Guard code”. The real response currently is an exception which means now that either the Steam API has changed or something else is completely wrong. Was short on time today but wanted you to know that it seems that there is really a change in Steam API according to reportings on the Steam Forums here. Other devs also noticed a change since this situation broke all current apps which use the Steam API.
I started evaluating and rewriting the login part so we add functionality again. Update was prepared and submitted but can take up to 5 workdays to get certified. Until then most probably the chat feature will not work as expected or not work at all. Sorry for that but this is not in our hand.