Error
Oh no, you encounted an error in GB Studio...
At this point before doing anything you should make a back up of you project folder just in case anything happens.
Once you've made a backup you may still be able to save your project using File / Save
in the menu. If this fails revert back to the backup.
Reporting Issues
If you've come across an error in GB Studio it would be greatly appreciated if you file an issue at: https://github.com/chrismaltby/gb-studio/issues
Getting Help
The best place to get help when GB Studio isn't working is either the Discord channel or on Reddit at /r/GBStudio.