GDevelop crashed or you found a bug? That’s not supposed to happen. 
Be sure to have the lastest version of GDevelop available on your platform. 
Some bugs have been already been reported to the GDevelop team, but they need more feedbacks, so you can take a look at this list of known bugs on Github.
To help us fix the issue, please report the bug on the forum and try to give as much information as possible :
- When the crash happened (the feature you were using, the window opened…)
- You can also send your project file with all the resources (optional)
- Feel free to record a video or share a project with the bug.
- Information about your computer (OS, Graphics card…)
- What is your current version of the GDevelop application.
If we are able to reproduce the issue thanks to this, then we will try to fix it for the next version of GDevelop.