Plant not assigned to Controlling area

Hi experts,

I am getting this error-Plant Z199 not assigned to controlling area (when creating sales order)

I have gone through OX19 and then OX18 for company code assignment to plant.

No clue on google. lot of people suggested lot of things.

Srinu S given some solution. But that is also not working.

No solution.

Kindly resolve.

Thanks & regards,

Supriyo