Unknown green screen pop up when trying to clear system cache?

[lomavista1205]

This is weird when I try to clean system cache a green screen pops up when I press volume up and power at the same time the language is in Korean and some English saying something about down loading so I use the volume down to cancel it I've cleaned it before but this is a first this happened 

[LongHiker]

@lomavista1205 Checkout https://www.samsung.com/us/support/troubleshooting/TSG01212623/ 

[lomavista1205 · Accepted solution]

Had to take my case off to push my volume up and power button to get to system cache wasn't pushing them both at the same time with the case on