InvoiceLineValidationError error message is not displayed correctly.
The message for the error InvoiceLineValidationError does not work correctly. As we can see the function check_same_account raise the validation error "InvoiceLineValidationError" shows the message "msg_invoice_same_account_line", this message use the variables: account, invoice and line:
raise InvoiceLineValidationError(
gettext('account_invoice.msg_invoice_same_account_line',
account=self.account.rec_name,
invoice=self.invoice.rec_name,
line=self.rec_name))
But if we look at the message file we can see that the message uses the variables: account, invoice and lines:
<record model="ir.message" id="msg_invoice_same_account_line">
<field name="text">You cannot use the same account "%(account)s" on invoice "%(invoice)s" and on line "%(lines)s"</field>
</record>
This means we have to change in the message the variable lines to line. And make this change in all the languages.