I had the same problem. Part of the answer is to manually create a table, because that is what that small section of code is doing (Create table if none exists). To do this, right click on the Table tab on the left of the screen, and then click to create a new table. Make sure to have the main.sql file open already, as then you can look at how you need to set up the table. It appears there is a coding issue with the code that they had their where the "clanid int(11)" and "auto_increment" weren't allowed to exist at the same time. I haven't run my server yet to see which was the better option (leaving the (11) or leaving auto_increment), but once I get the rest of my install done, I'll update this. As a note, after you create the new table- save a backup copy of that section of the code in a Notepad++ document and then delete that section of code from main.sql. The rest of the code should loan fine for main.sql. Also, make sure to refresh your schema so you see the rest of the tables if they did not show up (like moving on to the login changing portion of the tutorial). The refresh button is on the top right of the section that lists the tables and ragnarok and whatnot. It's a real small two arrows in a circle pattern pointing to each other.
EDIT 2: Instead of saving a backup of the code, you can just put "- -" (two dashes) next to it and it will treat it like the info writing that doesn't get read.
EDIT 3: So after choosing auto_increment with just INT, it looks like you might be able to pick INT and then type a (11) right after and then pick auto_increment to make sure you have all your data. If not, then choose auto_increment and leave the (11) off, finish filling out your table, and save it and then open it again and try adding the (11) next to the INT. Also, when I was having issues running main again after the main worked the first time but I couldn't find my other tables (I hadn't hit refresh), I ended up having to "- -" next to the "Insert into...." clan and one other line of code, because it had already inserted those values when it successfully ran once for me, and it was failing when it tried to do it again because the task was already done. My server is successfully running host side now. Now on to figuring out how to make a client work.