The Installation Failed -- Orchestra Library

I have downloaded Dorico on my new computer and everything is working fine aside from the fact that I can’t hear anything playback on the files I create.
The playback on the demos works fine.

I did the updates and successfully downloaded and opened PLAYBACK 1 - HALion Sonic SE3.

But when I download the Orchestra Library it all goes fine until I seemingly reach the last stage, when I get the message:
The Installation Failed.
The installer encountered an error that caused the installation for fail. Contact the software manufacturer for assistance.

Any help much appreciated

Though it is very big, I would try downloading the library installer again.
If you then still get that error, it is best to get in touch with our support:

Welcome to the forum, Matthew. My advice would be to try restarting your Mac and running the installer again before you run any other software, and hopefully you’ll find it will complete.

I can confirm that that error is not a single incident.

Last week I switched to a new machine - Mac mini - and opted to install every thing from scratch (not using TimeMachine).
At the very end of installing HSO, I encountered exactly the same problem; i.e. received that exact error message.
Please note: it was a brand new machine (i7, 16GB of RAM, 512GB SSD).
I can’t recall whether Cubase was already installed by the time I installed Dorico; i.e. whether it could have anything to do with that.
Luckily for me, on re-run the installation of HSO went through without a problem.
Yet, another weird thing happened on the first run of Dorico - the patch for Violin Solo Combi from the HSO didn’t load - i.e. no sound on entering notes nor on playback.
Again, luckily, deleting VST engine in Preferences fixed the problem.

A soft suggestion to the development team: for users who are not particularly computer savvy, the experience of installing Dorico could be a little bit less stressful, if the installation of all components - the app and the default libraries - were unified/streamlined.
Just a soft suggestion for the future.

Igor Borodin