May 01, 2014, 01:05:45 am
No.
Any prior versions can be retained on the system, as each is installed into it's own installation folder and there are no other shared components.
Note in terms of your files saved for imported objects and scenes, those made with earlier version 4 versions are stored in the same \Lumion 4 sub-folder and can be read by any version 4. As the
release notes mention, prior versions are not backwards compatible.
As there are some major changes, for example the new shadow system, it would generally be best to work forward in the versions.