Hello! I'm sorry you are having issues with the program. Please try this:
1. Navigate to the StimuWrite user data folder in your computer
Windows: %APPDATA%\Godot\app_userdata\StimuWrite\
macOS: ~/Library/Application Support/Godot/app_userdata/StimuWrite/
Linux: ~/.local/share/godot/app_userdata/StimuWrite/
2. Delete the file stimuwrite.cfg and the addons folder (if there is one )
3. Start StimuWrite
Let me know if this fixes the issue.