Hi there,
Thanks for reaching out. Adobe Illustrator CS6 was never tested to work on Windows 10. My recommendation would be to upgrade the app to the latest version.
You may also try resetting Illustrator CS6 preferences and see if it helps you out.
**Please note that resetting preferences will remove all the custom settings and Illustrator will launch with default settings. You can also take a backup of the folders in case you want to. Location is mentioned in the article.
Regards,
Ashutosh