Cause
This error appears in the Event Log while synchronising data, due to mismatch in voucher numbering method at the server and the client.
At one end the Method of Voucher Numbering is set to Manual and Prevent Duplicates is set to Yes. At the other end, the Method of Voucher Numbering is set to Automatic for the same voucher type.
Recording transactions at the server and the client will lead to identical voucher numbers at both the ends for the same voucher types. On activating the client rule, the server will display the following message:
404: Voucher Number ' 1' already exists! (FOR OBJECT: ' REMOTEID: 7806c76f-61a6-456b-a6d6-140fb75e6f52-00000003&apos 😉
Solution
Alter the Method of Voucher Numbering wherever it is manual to a different number and synchronize the data.