Entity 'Main Account' in DIXF

Hi Expert, 

I face a problem about creating processing group for main account. I want to upload COA trough DIXF, however I couldn't found entity 'Main Account' as picture below:

can someone help me?

Note:

I just setting a new Legal Entity in new environment. I ever try this way in other environment and it work well (with same treatment) as pict below:

why it can be different?

thanks in advance 

regards, 

Vira