Possible Solution #1:
Download: http://fixes.dungeondefenders2.com/No_Launcher.zip
- Extract the .zip
- Take both extracted files and place them directly into this folder: C:\Program Files (x86)\Steam\SteamApps\common\Dungeon Defenders 2\DunDef2\Binaries\Win32
- Double click the No_Launcher.bat that you copied over into the folder and the game should launch.
Possible Solution #2:
Try verifying your cache:
- Open your Steam library
- Right-click "Dungeon Defenders II" (http://i.imgur.com/UyPCa.jpg)
- Select "Properties" (http://i.imgur.com/JvLz2.jpg)
- Select "Local Files" (http://i.imgur.com/TO5wC.png)
- Select "Verify Integrity of Game Cache" (http://i.imgur.com/IZDGD.png)
Possible Solution #3:
On your computer, go to C:\Program Files (x86)\Steam\SteamApps\common, delete the folder named "Dungeon Defenders 2," then re-download the game.
Possible Solution #4:
We ask that you disable your firewall, including the one on your router/modem, VPN's (Like Hamachi) and any antivirus/threat programs you may have running.
Depending on your OS/Firewall, here are instructions on how to disable your Firewall: http://www.sevenforums.com/tutorials/542-windows-firewall-add-remove-exception.html
We understand users share their computer, so please make sure your account has Administrative rights.
Possible Solution #5:
Go to where the game is installed, and navigate to the following directory:
\Dungeon Defenders 2\DunDef2\UDKGame\Config
Then delete (or cut to a separate folder if you want to back them up in case it doesn't work) all the files that start with UDK. There should be around 14 of them.
Try re-running and see if that has an impact. You'll find the files will re-create themselves once you run the game.
Possible Solution #6 (Killer Network Cards Only): If your computer utilizes a Killer Network Card try getting their latest network drivers as some older drivers can cause issues in games like ours according to Killer. You can get the latest drivers here: Download Link
If None of These Work:
We're constantly working to fix any technical issues in Dungeon Defenders II. In order for us to learn more about your issue and find a potential solution, please follow these instructions. Thanks for your help!