Why is Minecraft 1.8 not working?

I play Minecraft on the 1.8 version but today I wanted to download the Lunar Server because a friend recommended it to me.

After I downloaded LunarClient, my PC got an error message saying that it has to be restarted.

After I did that, I immediately uninstalled LunarClient for fear of a virus and then I wanted to go into the normal Minecraft launcher, but it only stopped working for the whole 1.8 series. An error message appeared that an unexpected problem had occurred and there was still exit code: 0

I don't know if it was due to the Lunar Server but I hope someone can help me.

I play with the Lunar Client myself and have not had any bad experiences. I would recommend that if you forgot to log out of the lunar client, download the new one and log out, then delete it again and in the minecraft loucher simply log in again in the normal way.
I would do that if it works you have to try it.

Thank you for the info!

I've already done it like this:

I deleted almost everything from Minecraft in the folder and restarted the launcher, Minecraft then added it back by itself, but I would only have to add the Minecraft servers again.

I think your method would have helped me too, thank you very much!