FPGA Interface C API 2026 Q1 Bug Fixes

Created Feb 3, 2026

Overview

The following items are notable issues fixed between the release of FPGA Interface C API 2024 Q2 and FPGA Interface C API 2026 Q1, including additional patches and service packs. If you have an issue ID, you can search this list to validate that the issue has been fixed. This is not an exhaustive list of issues fixed in the current version of FPGA Interface C API.

Glossary of Terms

Bug Number	Legacy ID	Description	Details
		NI-RIO Fails to Install on Linux Kernel 5.13 or Later with Fatal Error When installing certain NI drivers onto a Linux system using kernel version 5.13 or later, the installation fails with an error about not finding all the dependencies it needs such as: /var/lib/dkms/nikal/21.5.0f129/build/nikal.c:32:16: fatal error: config/modversions.h: No such file or directory Workaround: Reattempt the installation after adding modversions.h to the kernel headers for your current system kernel. For example: sudo touch /usr/src/linux-headers-$(uname -r)/include/config/modversions.h	Reported Version: NI-RIO: 21.3 Resolved Version: NI-RIO: 2026 Q1 Added: May 10, 2022
3316026		When using the FPGA Interface C API, certain Double to Fixed-Point conversions can output incorrect data When using the FPGA Interface C API, Double to Fixed-Point conversions for values close to zero can output incorrect data. Workaround: There is currently no known workaround for this issue.	Reported Version: FPGA Interface C API: 2024 Q2 Resolved Version: FPGA Interface C API: 2026 Q1 Added: Oct 18, 2025

Bug Number

Legacy ID

Description

Details

NI-RIO Fails to Install on Linux Kernel 5.13 or Later with Fatal Error

When installing certain NI drivers onto a Linux system using kernel version 5.13 or later, the installation fails with an error about not finding all the dependencies it needs such as:

/var/lib/dkms/nikal/21.5.0f129/build/nikal.c:32:16: fatal error: config/modversions.h: No such file or directory

Workaround:

Reattempt the installation after adding modversions.h to the kernel headers for your current system kernel. For example:

sudo touch /usr/src/linux-headers-$(uname -r)/include/config/modversions.h

Reported Version:

NI-RIO: 21.3

Resolved Version:

NI-RIO: 2026 Q1

Added:

May 10, 2022

3316026

When using the FPGA Interface C API, certain Double to Fixed-Point conversions can output incorrect data

When using the FPGA Interface C API, Double to Fixed-Point conversions for values close to zero can output incorrect data.

Workaround:

There is currently no known workaround for this issue.

Reported Version:

FPGA Interface C API: 2024 Q2

Resolved Version:

FPGA Interface C API: 2026 Q1

Added:

Oct 18, 2025

Additional Patch Information

Installing some patches may require certain additional steps or considerations. Please refer to the following table for more information about patches for this release.

These patches currently do not have any special instructions.

Glossary of Terms

Bug ID - When an issue is reported to NI, you may be given this ID or find it on ni.com. You may also find IDs posted by NI on the discussion forums or in KnowledgeBase articles.
Legacy ID – An older issue ID that refers to the same issue. You may instead find this issue ID in older known issues documents.
Description - A few sentences which describe the problem. The brief description given does not necessarily describe the problem in full detail.
Workaround - Possible ways to work around the problem.
Reported Version - The earliest version in which the issue was reported.
Resolved Version - Version in which the issue was resolved or was no longer applicable. "N/A" indicates that the issue has not been resolved.
Date Added - The date the issue was added to the document (not the reported date).