It is often not possible to re-create all environment- or user-specific scenarios in a development environment. Of course, many application bugs or crashes happen without the developer present or a copy of Visual Studio running. In these cases, you can use tools to generate a dump file of the application state at the time of the issue.
Dump files save information about the state of your application. Dump files are typically created in response to a major bug or an application failure (crash). The dump file can then be sent to a developer. A developer can open the file and connect it with the source code and debug symbols to debug the state of the application at the time of the issue.