Error while creating a new document "The Value of the field Number is not unique"

Sometimes while creating a new document (for E.g. Customer Order, Invoice, etc.) you may face with the issue "The Value of the field Number is not unique.

The issue is connected to the fact that current prefix for the document was filled (due to the system architecture - 1 prefix may contain 999 documents).
For solving this issue you should change a prefix for the document ( in our example it is a Customer Order) ,  and system would start counting document numbers again.

Go to Administration > Service Settings > Document Prefixes:

You need to change Prefix for your document type (in our case it is a Customer Order):
Open Document prefixes link - system will show the window with Document Prefixes informational register.

You should find a Customer order in the list and change prefix to the  new one (for example  to CusO ).

After saving it - user should log out from the system and log in back (for the setting to be applied) and check new numeration.

Thank you for being FirstBit Customer!