With the release of Mac OS 10.14 (Mojave) last year, Apple, yet again, increased the security in its operating system with two new systems, "notarization" and "Hardened Runtime." Apple designed these so that the macOS can identify an application as being from a verified developer and apply restrictions on how an app is to be processed. This has been designed to prevent the execution of malicious code on your system. Although these systems were introduced in 10.14 macOS Mojave they were optional.
With the impending release of macOS Catalina (10.15) these will become mandatory. What will happen is that installers, which are not within compliance of Apple's security guidelines, will fail to install.
Hardened Runtime: This is a way to set a flag in the code of an application to apply a number of restrictions to an app when the application is processed.
Notary Service: This is a way for Apple to use a service to scan applications for malicious code that have opted into "Hardened Runtime."
What This Means For Studio One V4.5.3 And Above
With Studio One 4, build 4.5.3 and above, Presonus tell us that the .dmg installer file for Studio One 4, build 4.5.3 is now notarized and is compliant with Apple's security guidelines, which shows that DAW developers can be responsive and resolve these issues quickly. Although we have learnt that there was one entitlement not implemented correctly, which meant that VST plugins protected by iLok could not work, however, the good news is that was resolved in the 4.5.4 release. Now when you launch Studio One, it should simply open as designed, without requiring any changes to the security & permission settings on your Mac.
However, things are not so simple when it comes to 3rd party plug-ins PreSonus state in this Support Article
“If you are trying to load 3rd-party plug-ins that were created after June 1, 2019, the plug-ins must be updated by their manufacturers to support the "Hardened Runtime" and "Notary Service." Older plug-ins can be loaded if their code has been properly signed.”
If you have an issue we recommend that your first port of call should be the DAW developer and not the plugin developer. As we understand it, it is likely that the DAW developer will need to include the appropriate entitlement especially as the problem is likely to be because it is an iLok protected plugin that the DAW doesn’t have the correct entitlement for.
If you are trying to load 3rd-party plug-ins that were created after June 1st, 2019, the plug-ins must be updated by their manufacturers to support the "Hardened Runtime" and "Notary Service." Be aware that older plug-ins can be loaded if their code has been properly signed. If they are not properly signed, you may receive one of the following error messages:
Need To Use Older 3rd Party Plugins With Studio One?
PreSonus advise that if you need to work with a 3rd-party plug-in that is not yet compatible with the "Hardened Runtime" and "Notary Service," you have two choices…
Reinstall the 3rd-party plugin by right-clicking on the install before you run it and then select Open and so bypassing the restrictions.
Alternatively, you can delete the Studio One app from your Applications folder and download/install a previous build from within your my.presonus.com account. Just log into your account and go to My Products>Software>Studio One 4 and click the link to "View Previous Versions." You can then download and install a previous version. You can even have two versions of Studio One 4 installed if you would prefer. Simply download both .dmg files, and drag the apps into the Application folder.
Using An Older Version Of Studio One With macOS Catalina
If you do install a previous version of Studio One and you are running Mac OS 10.15 (Catalina), you will need to ctrl+click the .dmg installer file and choose to open with DiskImageMounter. Once installed to your Applications folder by dragging the app into it, you can open the app and click 'Open' when the error pops up.
Alternatively, you can navigate to the System Preferences > Security & Privacy, unlock as Administrator, and hit "Open Anyway" to suppress the warning.
Studio One Not Compatible Yet With macOS Catalina
Despite all of the above PreSonus have stated as far back at June 17th 2019, just 2 weeks after Apple announced macOS Catalina, Presonus published this warning on their website…
“Apple’s latest upcoming Operating System Mac OSX 10.15 (Catalina) has started its Public Beta Phase. As Apple's Public Beta progresses, changes will be made to their Beta builds along the way.
Should you be part of Apple's open public Beta, the versions shared to the public (prior to the actual commercial release) do not fully reflect the final version that is actually approved for commercial usage.
Until such time as PreSonus has fully reviewed its products after Apple has officially released the commercial version of OSX 10.15, compatibility and usage of OSX 10.15 Beta Version is at your own risk and PreSonus Support will defer you to Apple's Beta Program for further information.”
You have been warned.