Error 1045 When Using the LabVIEW Report Generation Toolkit

Updated Mar 24, 2021

Reported In


  • LabVIEW
  • LabVIEW Report Generation Toolkit

Issue Details

When I run a VI that uses the Report Generation Toolkit I get Error 1045, as seen in the screenshot below:

Error 1045 occurred at Unknown System Error in ACTIVE X reading Excel Worksheet Names

Possible reasons:
LabVIEW: Null Refnum passed to Close Reference.

This program used to work in a previous version of Microsoft Excel and LabVIEW but after updating the Excel version it is throwing this error, how can I fix this?


Follow these steps to troubleshoot the issue:
  1. Verify the compatibility between the Report Generation Toolkit and Microsoft Office version. Please take a look at the table in this link. If any software components are not compatible, upgrade LabVIEW or Microsoft Office to a compatible version.
  2. If you have a newer version of LabVIEW installed on the same computer, try running the VI in that version.
  3. Try changing the ActiveX reference for the Excel application to a newer version, if none is available it might mean that the LabVIEW version is not compatible with the version of Excel being used.