Because of Dragon's Prophet often having many issues, I'm going to be compiling a list of common issues, and fixes for them. Missing D3DCompiler_43.dll To fix this issue you should install the library from the following link: Download DirectX End-User Runtimes (June 2010) from Official Microsoft Download Center - https://www.microsoft.com/en-us/download/confirmation.aspx?id=8109 Other Missing DLL To fix this issue you will need to install this library from the following links: Download Microsoft Visual C++ 2010 Redistributable Package (x64) from Official Microsoft Download Center - https://www.microsoft.com/en-us/download/details.aspx?id=14632 Download Visual C++ Redistributable Packages for Visual Studio 2013 from Official Microsoft Download Center - https://www.microsoft.com/en-us/download/details.aspx?id=40784 "Unknown Error (-1)" when logging into game This error happens when you're unable to find a route to host, and usually has something to do with your ISP or computers DNS cache. If you get this issue you can either wait it out, or use one of the following to try to fix it: Use Google DNS (best method): Get Started | Public DNS | Google Developers - https://developers.google.com/speed/public-dns/docs/using Flush your DNS Cache (may not work): How to clear the DNS Cache on a computer and web browsers? - https://support.opendns.com/hc/en-us/articles/227988627-How-to-clear-the-DNS-Cache-on-a-computer-and-web-browsers- "Unable to log in to the server" If you get this message when logging in you probably do not have a proper configuration file for our server. You will need to go to your install directory for Dragon's Prophet (our client) and modify the client.ini file to have the following code: Code: [Server] Ip=server.dragonsprophet.online Most other issues Many issues on Dragon's Prophet can be cleared by clearing the contents of the "My Documents\Dragoon" folder and the "Dragons Prophet\cache\server.dragonsprophet.online\" folder. This may need to be done when you have logged out from EU.