as with any major update, a factory reset is highly recommend to untangle any issues that may arise.
recommend to uninstall the launcher, or may sure its compatible with the current firmware os.
if you are rooted this takes on a different discussion.
the latest (as of this writing) android update changes the way apps can access folders on SD card. this is for security reasons and has been discussed all over the internet. this could also be the reason some of your apps are not working.
if you have moved any apps to SD card that are not currently working, move them back to internal storage, or just move one or two back and test.
you may have to uninstall apps and re-install.