Duplicate number sequence error "Voucher ### is already used as of date ###"

When you post the voucher if you may get below type of error, you have some duplication's on the voucher number. 

Solution:

Go to Account Payable > Setup > Account payable parameter

There click Number sequence right click with particular voucher number sequence and go to view details.

Edit the number sequence and select the status list in top of the number sequence form

You can see one form with the name of status of number sequence with some pending number are in pending stage.

Select this line and delete it, then close the status form.

Then click the Manual clean up button in that select the current one. It will take to clean all the duplicate number sequence which are in waiting stage.

Now save the particular number sequence then close the form and make the transactions.

You will get the positive response with this.

(or)

Even if it is not working then you can create a new number sequence.

Go to Account Payable > Setup > Account payable parameter

Again click Number sequence right click with particular voucher number sequence

Create a new Number Sequence and put same number sequence which you got error and put the Next number “#” and select the Continuous if you want as automatically otherwise select manual and Save it.

Now your number sequence will work for the transactions.