It is important to upgrade the version of 4D, especially if there is a stability issue encountered or if the environtment is being updated. It can be difficult to upgrade between major versions of 4D, however, upgrading between minor versions should not be difficult.

With LTS version each new minor version will mostly contain bug fixes and security-related updates. There should not be many new features that might cause a regression. With all of these fixes, the differences between minor versions could be significant. With the current version of 4D at the time of this Tech Tip, 4D 20, the minor versions span over a year, not including beta releases and nightly builds.

According to product-download.4d.com:
4D 20.0 was released on July 7th, 2023 and 40 20.6 was released on January 31st, 2025
https://product-download.4d.com/?branch=20.x&flag=lts-release&version_number=All&platform=win&type=installer&build=

That is over a year and a half of bug fixes that could be missing. As such, if possible, it is always highly recommended to stay on the latest minor releases of the version of 4D being used to be as stable as possible.