(Support ticket #3367754)
Hit there; I hope this is the right category. For the better part of a week I have been almost completely unable to play the game, as it fails to appear at all after hitting 'Play' on the launcher.
The step-by-step:
Launch Warframe through Steam
Press 'Play' on the Launcher
The launcher closes, but the game itself never appears. No other messages appear on-screen to indicate an issue is occurring.
Steam still thinks Warframe is running, and the task manager shows Warframe running as a background process (as per the image below)
Stopping the game via Steam closes the background process.
What I've tried so far:
Restarting my PC.
Verifying the game cache through the launcher.
Optimising my download cache.
Updating my video drivers.
Deleting and redownloading the game through Steam (then restarting my PC). After re-downloading the game, the launcher downloaded a few GB of patches, and optimised the download cache. It appears the launcher is working in every capacity except the one it was named for.
Running in DirectX 12 mode.
Launching the Warframex64.exe file manually from the game files (nothing happened, no background process either)
Resetting my video drivers as per the steps in this stickied thread.
Uninstalling Overwolf Thunderstore, the installation of which vaguely appeared to coincide with the issue's appearance. It's a program I used to install Lethal Company mods, but at one point it created a pop-up offering me a 'Warframe Helper' app to track what gear I've mastered (which I dismissed; I never installed the offered program, but it appeared to detect that I was running Warframe to offer it to me). On inspection it seems innocuous enough, but I figured it was better safe than sorry.
After doing all of the above troubleshooting steps, I found that the problem still persisted; strangely, however, upon returning some hours later I was able to launch the game twice in succession, despite the only apparent difference being that I'd turned the PC off and on again (again). It wasn't to last, however, as this morning the issue returned. After it started happening again, I restarted my PC and launched Warframe before doing anything else, to no avail.