Can't select size as a variation when listing?

[rugby_stuffuk]

Hi guys, I'm new to listing variations and have just watched a video guide. I've hit a road block - when I select 'create variation', I cannot select size. There is only 'gender' and 'MPN' as an option and when I type 'size', it says 'this attribute isnt valid for this variation'. The category is rubgy league t-shirts.. Any idea what I'm doing wrong? Thanks in advance.

[robxznyc]

This is my variation screen. You need to select Size Type, Regular, and then you'll see the size options. Select the sizes you need and click add. 

 

[rugby_stuffuk]

Thanks for your reply. As you cans see, size isn't an option. Could this mean that size isnt available in this category? Its rugby league - shirts, so size shoudl be an option!

[trangbui55]

Need Remove Size Type Before This Page and After you need Detele MPN and GENDER vs..

After Add