[Error Message] Complete noob when it comes to MyBB. "Warning [2]"

[MaximHF]

Can you check the content of the "inc/config.php" file, and post it here (but remove your database username and password first)?

Thank you.

Here: DELETED

I accessed the index of my site and it told me to lock the install folder. So i did that by creating a file and naming it locked.

Now it updated the error to this:

MyBB has experienced an internal error and cannot continue.

Error Type:MyBB Error (42)Error Message:Your board has not yet been upgraded. Please do so before attempting to browse it.

Thought that i installed the most recent version. 
Should i just try to download the same version and replace it?

Edit: Reinstalled it and now i didn't get the Warning message. Now i can proceed with the install that i couldn't before.