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FlexLogger 2021 R4 Known Issues

Created Sep 8, 2026

Overview

This document contains the FlexLogger known issues that were discovered before and since the release of FlexLogger 2021 R4. Known issues are performance issues or technical bugs that NI has acknowledged exist within this version of the product.
 

Not every issue known to NI appears on this list; it is intended to show the most severe and common issues that you may encounter and provide workarounds when possible. Other technical issues that you may encounter could occur through normal product use or system compatibility issues. You may find more information on these issues in NI’s Product Documentation, Knowledgebase, or Community.

Bug Number

Legacy ID

Description

Details
453982

Windows Throws a Blue Screen Error When a PXI-653x Card is Deleted in NI MAX

Windows may throw a blue screen error when a PXI-653x card is deleted in NI MAX while a project that has one or more channels configured on that card is open in FlexLogger. This error occurs because FlexLogger is running a task and the driver does not correctly handle the interruption.

Workaround:

Close the FlexLogger project before deleting a PXI-653x card in NI MAX.

Reported Version:

FlexLogger 2021 R3

Resolved Version:

N/A

Added:

Jul 27, 2021
1695510

Run Button Remains Disabled After Changing a Logging Specification Setting

The Run button may remain disabled after you change a setting in the Logging Specification.

Workaround:

Click anywhere in the application to re-enable the Run button.

Reported Version:

FlexLogger 2021 R4

Resolved Version:

N/A

Added:

N/A
1664955

FlexLogger Throws an Error When Multiple Alarms Trigger Rapidly and Regularly

FlexLogger may throw a compile error when running a test where multiple alarms trigger rapidly and regularly. This can happen when using a simulated device. The periodic nature of the simulated signals causes alarms to trigger every second.
 
The compile error states the following:
"An unexpected error related to alarm processing has occurred. It is recommended you restart FlexLogger or contact NI support at ni.com/support."

Workaround:

Ignore the error and continue to run your test. Alternatively, you can stop the test and FlexLogger will clear the error.

Reported Version:

FlexLogger 2021 R4

Resolved Version:

N/A

Added:

N/A
1665871

Python API Method TestSession.start() Returns True When a Test Has Not Started

When you call the Test Session.start() Python API method while FlexLogger is reconfiguring channels, the method may incorrectly return True, indicating that the test has started successfully when it has not. This can happen when FlexLogger is loading a project.

Workaround:

Call TestSession.start() and then query TestSession.state to confirm the test has started. Run this logic in a loop until the test starts. The code is provided below.
from flexlogger.automation import TestSessionState

while test_session.state != TestSessionState.RUNNING:
    test_session.start()

Reported Version:

FlexLogger 2021 R3

Resolved Version:

N/A

Added:

N/A

Final Time Issue Listed

Issues found in this section will not be listed in future known issues documents for this product.

There are currently no issues to list.

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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).