This issue has popped up a few times and may be caused by files not being deleted or overwritten during the upgrade processes.
Please do the following
first try deleting the spark profile located folder %appdata%\Spark (this will delete your history and settings so you may want to back this up). launch spark. Did this resolve the issue?
If that doesn’t work - try going to add remove programs and uninstall spark. Then go to the spark installation folder. Are there any left over files? If so, please make note and report them. Afterwards, delete the install folder and the spark folder in %appdata% again. Reinstall spark. Did this work?