After reinstalling os x and updating it to Sierra I found that Reason 7 would not start. Instead the following error message is displayed:

Unknown installation error
An error occurred during installation of installed files. Contact support or reinstall the application. Now terminating.

Unknown installation error

I searched around on the web and found that it's common to have problems using Reason 7 on Sierra, there are various things people have tried, one thing I tried was to start the Reason 9 demo and then to start Reason 7, but this didn't work for me, also, at the time my Reason 9 trial had expired. see: Reason 7 on mac sierra os x issues? reason stops supporting

I have found that I am able to start Reason 7 using an unconventional method.

First I open the reason folder in finder, then select "Show Package Contents"

Show Package Contents

This allows me to navigate to locate the Reason unix executable at Reason.app/Content/MacOS/Reason

MacOS folder inside Reason.app

When I execute the Reason file, reason starts up and I can use it normally. I can use my ignition key and after installing the latest version of code meter (6.50b from the codemeter.com) and installing Authorizer using Authorizer.pkg (from the Resources folder inside Reason.app) I was able to auhorize my computer to run reason without the ignition key. If you try this and find that the web page says it can't find code meter, try pressing the reload page button on your browser.

My question is: how can I start reason without having to go show package contents and invoke the Reason executable directly?

It's seems clear that something extra is happening when I double click the reason.app icon that causes the error, how can I get it to skip that and execute the Reason executable only.

I've searched around in the Reason.app folder and I imagine that there's something in there that I need to change so that it will invoke the Reason executable immediately instead of trying to install things at start up.

2 Answers 2


To add to the answer, the solution would appear to be found in the following link:


The folder in question in application support should be deleted in order for Reason 9 to launch. This should fix the issue.

  • Deleting that folder does not fix anything for me.
    – dbt
    Commented Nov 11, 2017 at 12:14

I've managed to find a stable fix and make Reason 7 work on Sierra(no bugs and fully stable) and now Mojave as well(some visual bugs and stable so far), so I suppose the method will work on any OSX and possibly with any outdated version of Reason.


  1. I reinstalled the stock OSX (Mountain Lion in my case) that comes with the Macbook factory - Internet Recovery boot.(alt-hold while booting + wifi/ethernet + cmd+R)
  2. Then I installed Reason 7 first thing and opened a project.
  3. Updated OSX to latest version (in this case Mojave).
  4. Open Reason. All is good.

Some notes:

Visual Bugs(probably because of the new black/white theme algo):

  • the icons on the main open app splash for authorisation / online log in / demo mode do not seem to show up - everything clickable tho.
  • the right-side overview(rack/mixer/sequencer) visual-scroll-bar appears to be blank but works fine.
  • also the in-app browser doesn't seem to show the native osx folder icons. Other than that all is good.

Worth mentioning:

  • In case your icloud/apple account doesn't seem to log in or sync after update (this seems to be a current issue on latest osx versions) you can fix this easily by creating a new admin account and just migrate (preferably at the beginning) to this new account and delete the old one.
  • I recommend upgrading to the latest versions of course although some older macs will not work well with more recent Mac OS, also Reason compatibility or overall performance is tricky to maintain for some of us, so until then this is the best solution.

Update: Found another visual bug - the pianokeys or drumkeys in the sequencer song-edit mode do not show up, again clickable but not visible. (This is a major nono for me so I had to revert to sierra which is best so far) Also I wouldn't call Mojave stable anymore - 1/10 times Reason fails to open in a crash, although opens right away the second time. Sierra is the way to go.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .