Today I just reinstalled Minecraft on my PC everything was fine until at the time of "Play" it appears "You seem to be playing a modified version of the game that is not compatible" (I guess it must be because I downloaded LabyMod or not he)

I only ask you to help me solve this problem because with these changes of Minecraft I did not even know as I said, I just installed it again

I want to add that something different happens to me when I start the launcher with any version.
I get this