Wiping the cache and data had no effect. FINALLY told that I had to re-flash the phones OS
After 9+ years with only Blackberrys I just purchased an S8+.
I love being able to use themes again and before i even had the device completely set up I was off and theming and got a bit lost between different launchers and losing Google.
doing a wipe back to factory was a breeze.
Hold the Volume up, Bixby, and Power buttons at the same time, and keep them held down until you see the Samsung logo.
After 30 seconds, you should see the Android Recovery Menu. ...
Press the Volume down button four times, until Wipe data/Factory reset is highlighted. Take only about 30 seconds to wipe.then hit the "Reboot" "yes" and the Samsung Logo will appear. For about a minute, nothing will happen.. Wait! the OS will download automatically and you'll be back with everything updated.
After doing this many times, I decided to do the entire set up with the original theme including setting. Then, I was able to theme away.
I found that if i signed into google first then into my Samsung account I did'n't lose Google.