Error in Transaction VL01NO

Hi Experts,

I am facing a problem while executing VL01NO transaction. The business scenario is as follows:

Step 1: Create a delivery order with material ABC and Qty 10.

Step 2: Save the DO

Step 3: Re-entered the DO and deleted the material ABC and saved the document.

Step 4: In change mode (VL02N) i tried to enter the same Material ABC and Qty 5. Then press the enter button.

Step 5: Getting an error message as shown below:

Material XXXX is not defined for sales org. XXXX distr.chann. lang. EN

Kindly advice how can i provide a permanent solution to this issue.

Thanks & Regards,

Sharan