Yosemite on an old Core2 iMac didn't like this new version.
Snippet from report:
Process: ZettelKasten-Qt [622]
Path: /Volumes/VOLUME/ZettelKasten-Qt.app/Contents/MacOS/ZettelKasten-Qt
Identifier: org.zettelkasten.ZettelKasten-Qt
Version:

Code Type: X86-64 (Native)
Parent Process:

[1]
Responsible: ZettelKasten-Qt [622]
User ID: 501
Date/Time: 2021-01-08 12:51:59.797 -0500
OS Version: Mac OS X 10.10.5 (14F2511)
Report Version: 11
Anonymous UUID: F2410621-1414-EB30-4A2D-29AF43C1A0E7
Time Awake Since Boot: 870 seconds
Crashed Thread: 0
Exception Type: EXC_BREAKPOINT (SIGTRAP)
Exception Codes: 0x0000000000000002, 0x0000000000000000
Application Specific Information:
dyld: launch, loading dependent libraries
Dyld Error Message:
Library not loaded: /usr/local/Cellar/openssl@1.0/1.0.2t/lib/libcrypto.1.0.0.dylib
Referenced from: /Volumes/:Users:zettelkastendev:Desktop:QQQ:build-zettelkasten-qt-Desktop_Qt_5_9_9_clang_64bit-Release:ZettelKasten-Qt/ZettelKasten-Qt.app/Contents/Frameworks/libssl.1.0.0.dylib
Reason: image not found