Compatibility issues you might encounter upgrading to LabVIEW 2021.

Python Support

LabVIEW 2021 supports Python 3.6 through 3.9 and removes support for Python 2.7.

Run When Opened

When a user launches a VI that is configured to run when opened from a disk location other than standard NI installer locations, such as the LabVIEW 20XX or National Instruments\Shared folder, the user will be prompted to choose whether to run the VI or open it in edit mode.

nicurl Uses System Certificates on Windows

nicurl uses the OS certificate store on Windows rather than its own HTTPS certificate bundle.

OS Support

LabVIEW no longer supports Windows Vista/XP/7/8.x, Windows Server 2003/2008/2012, or any 32-bit Windows operating system.