Dynamics Community Forum Thread Details

D365FO ER: "List is empty" error for TaxTrans/ExemptCode in Free Text Invoice report

We are experiencing an issue while running an Electronic Reporting (ER) format for not posted Free Text Invoices in Dynamics 365 Finance & Operations (D365FO). The report fails with the following error message:

"An error occurred during the 'Format mapping' run. Evaluating expression for path 'TaxTrans/ExemptCode'. List is empty at 'model/LineItem/TaxTrans'"

Context & Setup:

Model Mapping:
- TaxTrans is linked to LineItem in the model (Invoice line - item(LineItem) = CustInvoiceJour.'$CustInvoiceTrans_OrderByLineSeqNum')
- The reference path for TaxTrans is: CustInvoiceJour.'$CustInvoiceTrans_OrderByLineSeqNum'.'$TaxTrans_All' (Tax transaction(TaxTrans) = @.'$TaxTrans_All'
- It is correctly mapped in the Model Mapping Designer.
Format Mapping:
- The ExemptCode is mapped using: IF(@.TaxTrans.ExemptCode<>"", @.TaxTrans.ExemptCode, "")
- The LineItem section correctly retrieves data, except when TaxTrans is empty.

Troubleshooting Steps Tried:

Added a Condition to Prevent Empty List Errors:

IF(COUNT(@.TaxTrans) > 0, IF(@.TaxTrans.ExemptCode<>"", @.TaxTrans.ExemptCode, ""), "")
- This still causes the "List is empty" error.
Attempted Using ALLITEMSQUERY to Retrieve Tax Transactions:

ALLITEMSQUERY(CustInvoiceJour.'$CustInvoiceTrans_OrderByLineSeqNum'.'$TaxTrans_All')
- This led to validation errors stating "The parameter of ALLITEMSQUERY function must be a valid path to a datasource element of the 'record list' data type."
Tried Using FILTER to Process Only Non-Empty Tax Transactions:

FILTER(@.TaxTrans, COUNT(@.TaxTrans) > 0)
- But we got "The list expression of FILTER function is not queryable."
Considered Returning an Empty List When TaxTrans is Empty:

IF(COUNT(@.TaxTrans) > 0, @.TaxTrans, EMPTYLIST(@.TaxTrans))
- This did not resolve the error either.

Question:

✅ How do we safely reference TaxTrans.ExemptCode in the format mapping to prevent the "List is empty" error when TaxTrans has no records?

Additional Questions:

Is there a better way to prevent ER from attempting to evaluate TaxTrans when it is empty?
Should this issue be handled in the Model Mapping, or is there an alternative approach in the Format Mapping?
Is there a known workaround for making TaxTrans optional without causing errors?

Any guidance or best practices would be greatly appreciated! Thanks in advance for your support. 🙏

Categories:

Dynamics 365 Finance

Hi,

First of all: Good job with the information provided and the effort of trying.

Approach 1:

I think this is the issue.

IF(COUNT(@.TaxTrans) > 0, IF(@.TaxTrans.ExemptCode<>"", @.TaxTrans.ExemptCode, ""), "")

I handle the similar issue like the following. I know I am using the TaxTrans.Rate here, that is a number.
 
IF
(
    NOT(ISEMPTY(model.'$ProjectList'.'$LineEmployee'.TaxTrans)),
    model.'$ProjectList'.'$LineEmployee'.TaxTrans.Rate,
    0.0
)
 
 
 
Your case would be:
 
IF
(
    NOT(ISEMPTY(@.TaxTrans)),
    @.TaxTrans.ExemptCode,
    ""
)
 