Problem in General Journal

Dear all,

I am entering first Journal Voucher entry in General Journal. I have assigned, No. series to this Batch.

But this No. series is not appearing in General Journal(Document no.). I entered Document No. Manually and completed the entry in first row( i.e. Debit entry), When I am moving towards the second row( for credit entry)

I am getting one error message

" The Gen. Journal Line already exists

Identification field and values

Journal Template Name =“General”

Journal Batch Name =‘Gen-Jou’

Line No.=‘10000’ "

So, My question is , why No. series is not reflecting automatically in this Journal Batch, and Why this error message is coming ???

Please note , this is the first Journal entry, I am passing in General Journal

make sure that the No series is marked as “default”