SERVICE-Bug or Error in "Serv. Document Log" Table

NELLIO

Hello,

I create an Invoice in Nav Service, for example N°1000.
In the "Service document Log" table i've a record with "Document type" = Invoice and with "Document number" = 1000 which is automatically insert.
When i post my Invoice N°1000 ... the system not delete the record with "Document Type" = Invoice and with "Document number" = 1000 in "Service Document Log" table but delete the invoice N°1000 ... so i've a error message when i test my database !!

Can someone explain to me what's wrong or if it's a bug ?

Thanks in advance.