Is trial overwriting my legitimate Matlab installation?

I have a paid-up installation of Matlab R2015a and many toolboxes. I want to try two other toolboxes and requested/received a trial for them via the License Center. When I downloaded the trial , I seemed to have to download Matlab too: popup window said 'Removing files for Matlab', followed by a popup window saying 'Downloading Matlab', ... etc. The trial installation seemed to undo my 'legitimate' installation, yet the trial toolboxes were not available after the installation. What is the correct way to install only trial toolboxes while leaving my existing installation intact?

Answer 1

[the cyclist]

On my Mac, the trial download does not overwrite a prior installation. It installs in, for example, /Applications/MATLAB_R2015b (where the prior version was in MATLAB_R2015a).

[Walter Roberson]

R2015b is not released yet, so are you sure you are talking about Trial and not Beta ?

[the cyclist]

Ah, right. Somehow I confused pre-release and trial.