Troubleshooting Guide for CFP Add-in for Excel 365

Last updated on 2026-01-08

Overview

This guide serves as a central resource for resolving issues you are facing with the CFP Add-in for Excel 365 efficiently.

Each entry includes the problem description, root cause, and the steps taken to fix it.

The page will be amended continuously to ensure ensuring fast, consistent problem-solving.

Lucanet formulas show the prefix 'xldudf_' (e.g., "_xldudf_LN_VALUE")

Error Description

You work with the Lucanet.Excel Add-in and notice that your Lucanet formulas are displayed with the prefix xldudf, e.g. xldudf_LN_VALUE instead of their expected format (LN.VALUE).

This indicates that Excel cannot recognize or resolve the custom Lucanet functions such as LN.VALUE(), LN.ATTRIBUTE(), and other LucaNet-specific formulas used to retrieve data from Consolidation & Financial Planning (CFP).

When Does the Error Occur?

The error typically occurs when two or more versions of the Lucanet.Excel-Add-in are installed and active simultaneously:

Lucanet COM add-in - the legacy Lucanet.Excel-Add-in

CFP Add-in for Excel 365 – the modern Office 365-compatible version

Since both add-ins use identical formula names, Excel cannot determine which version to execute, causing the function resolution to fail.

How to Fix the Error

To fix the error, you mus deactivate the legacy Lucanet.Excel-Add-in while keeping the CFP Add-in for Excel 365 active. Proceed as follows:

Open Excel and go to File | Options.

In the Excel Options dialog, navigate to Add-ins in the left sidebar.

From the Manage dropdown list, select COM Add-ins and click Go.

Excel options

Deactivate the checkbox for Lucanet COM add-in.

Click OK.

Close and restart Excel.

After restart, Lucanet formulas will display correctly without the xldudf_ prefix. The COM add-in remains on your system and can be reactivated if needed.

What Does This Mean for my Workbooks?

Deactivating the COM add-in does not delete it from your system - it simply prevents it from loading when Excel starts. You can reactivate it later if needed by following the same steps and activating the checkbox again.

The CFP Add-in for Excel 365 will handle all Lucanet formula calculations going forward.