Hi Vijay,
you should create number ranges and then check if same is assigned to your Warehouse i.e. 01 or 02 and you should create number ranges for Warehouse warehouse task and warehouse orders as well.
The screens which you have attached, does not give a enough details about the issue, please activate the log for warehouse task as advised by Suraj in previous reply, and then try again and post the log details.
Regards
Anoop