This demo helps Fix Internal Error dialog box while trying to run or open some app (ex, Adobe Illustrator, Evernote) on your Mac computer.
Solution 1: Save your job > restart your Mac > re-try opening the app later. Solution 2: Back up your personal data, then try the below options: Uninstall the problematic/BETA version of app using the recommended app remover PRO in this vid > use the stable/ latest one.
(from: quora.com) Reset the System Management Controller (SMC).
Other options are: 1. Use Disk Utility to repair or erase your startup disk or other hard disk > (BACK UP your personal data first!) Restore your Mac > Reinstall your Mac.