T3-blank template "layout" plan dissappeared !!!

Hi,

I am working on new website using t3-blank template, while I updated the image logo, after that, I found that the module on the right-hand side disappear, so I go to t3-blank template -> click the layout tab and found that the layout plan disappeared, can everybody tell me what happen, how can I resume the layout plan, thanks in advance.


Ok, when I click some tab, it resume but it reset all position name to default! so weird!!!