Cubase Pro 8.5 won't start on MacOS 10.15.7

I’ve been using Cubase 8.5 on a Windows 7 PC without any issues ever since it was first released, but that PC has just died so I need to get Cubase on my MacBook Pro which is running Catalina 10.15.7.

I downloaded the latest versions of the elicenser software and Cubase 8.5 installer from Steinberg and both installations seemed to go fine. However when I try to open Cubase I can only get as far as the Steinberg Hub. For an instant the content in the left-hand (news and tutorials) pane is displayed but it then disappears, which I thought is a bit odd. If I then try to open a project or create a new project, it just crashes and I get an error.

I’ve tried reinstalling but it’s made no difference. I can’t paste the full error below a this forum has a character limit for posts, so I’ve just included as much as I can. Hopefully that’s the relevant stuff but if not please let me know and I can find specific parts to post. Can anybody help? Until I can get this resolved I’ve essentially got no studio :frowning:

Process: Cubase 8.5 [831]
Path: /Applications/Cubase 8.5
Identifier: com.steinberg.cubase8v5
Version: (
Code Type: X86-64 (Native)
Parent Process: ??? [1]
Responsible: Cubase 8.5 [831]
User ID: 501

Date/Time: 2021-09-27 20:32:14.828 +0100
OS Version: Mac OS X 10.15.7 (19H2)
Report Version: 12
Bridge OS Version: 4.6 (17P6610)
Anonymous UUID: 49242F75-CA7A-42C1-A57A-F36073A14421

Time Awake Since Boot: 730 seconds

System Integrity Protection: enabled

Crashed Thread: 0 Dispatch queue:

Exception Codes: KERN_PROTECTION_FAILURE at 0x00007ffeddd54920

Termination Signal: Segmentation fault: 11
Termination Reason: Namespace SIGNAL, Code 0xb
Terminating Process: exc handler [831]

VM Regions Near 0x7ffeddd54920:
MALLOC_LARGE 00007f9e36b5a000-00007f9e36bff000 [ 660K] rw-/rwx SM=PRV
→ STACK GUARD 00007ffeddd54000-00007ffeddd55000 [ 4K] —/rwx SM=NUL stack guard for thread 0
Stack 00007ffeddd55000-00007ffee1554000 [ 56.0M] rw-/rwx SM=COW thread 0

Thread 0 Crashed:: Dispatch queue:
0 libsystem_pthread.dylib 0x00007fff69421bf0 ___chkstk_darwin + 96
1 0x00007fff31a0a20a -[NSISEngine _coreReplaceMarker:withMarkerPlusDelta:] + 140
2 0x00007fff31a0a110 -[NSISEngine constraintDidChangeSuchThatMarker:shouldBeReplacedByMarkerPlusDelta:] + 243
3 0x00007fff31a09fd5 -[NSISEngine tryToChangeConstraintSuchThatMarker:isReplacedByMarkerPlusDelta:undoHandler:] + 410
4 0x00007fff31a01fd5 -[NSLayoutConstraint _tryToChangeContainerGeometryWithUndoHandler:] + 389
5 0x00007fff319f4ae4 -[NSLayoutConstraint _setSymbolicConstant:constant:] + 553
6 0x00007fff319f7b80 -[NSLayoutConstraint setConstant:] + 66
7 0x00007fff2ceca34f -[_NSOldSchoolAdapter accFrameChanged:] + 102
9 0x00007fff2f3407a3 ___CFXRegistrationPost1_block_invoke + 63
10 0x00007fff2f340718 _CFXRegistrationPost1 + 372
11 0x00007fff2f340384 ___CFXNotificationPost_block_invoke + 80
12 0x00007fff2f3104fd -[_CFXNotificationRegistrar find:object:observer:enumerator:] + 1554
13 0x00007fff2f30f9a9 _CFXNotificationPost + 1351
14 0x00007fff2c5fba1f -[NSView _postFrameChangeNotification] + 304
15 0x00007fff2c5f4684 -[NSView setFrameSize:] + 3248
16 0x00007fff2c60603e -[NSView setFrame:] + 423
17 0x00007fff2c6775d5 NSViewActuallyUpdateFrameFromLayoutEngine + 279

Cubase 8.5 is simply too old to be run on Catalina. The last supported OS for Cubase 8.5 was MacOS 10.12. Updating to Cubase 11 will most probably solve your problem.