What is the MYBB root folder, and a Admin in my forum is questioning me that whenever he installs a plugin and tries to add it in the forum it says ''Upload it into MyBB RootT Folder/Inc/Plugin. What are those thing?
Root folder is the folder where your forum is installed. e.g. if your forum is installed on
http://yourdomain.com/forum/ then ./forum/ is your root folder.
It's where you uploaded the MyBB files. Not the root of your web server though.
Where are you hosted at? Are you using one of those free forum websites?
/beaten
You login to the FTP using a program like
FileZilla.