Minecraft supposedly no license?

I bought Minecraft Pocket Edition legally in the Play Store, and when I open the app it says, "Apparently you do not have a Minecraft license, make sure you download and install Minecraft through the store."

I've already installed it again and again, but it still does not work.

Does anyone have a solution for this problem?

Call support and have your bill ready.

Delete the cache from the game and from the Playstore.
Check your internet connection.
Remove your Google account on the device and add it again + Repeat 1.

If nothing helps you should contact the support. They will definitely help you.