The latest version of the client produces this when launched on Mavericks.
Here is the log produced by /Applications/nextcloud.app/Contents/MacOS/nextcloud --logfile ~/Desktop/nc.log.txt:
12-07 11:12:45:067 3101 OCC::Application::setupLogging: "################## Nextcloud en_US () 2.3.3 (build 84) on OS X Mavericks (10.9)"
12-07 11:12:45:067 3101 OCC::Application::setupTranslations: void OCC::Application::setupTranslations() Using "en" translation
12-07 11:12:45:067 3101 OCC::Application::Application: Loading global exclude list
12-07 11:12:45:067 0x7ff591c13eb0 csync_exclude_load: Adding entry: *~
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: ~$*
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: .~lock.*
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: ~*.tmp
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: ]*.~*
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: ]Icon
*
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: ].DS_Store
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: ].ds_store
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: ._*
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: ]Thumbs.db
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: desktop.ini
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: System Volume Information
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: .*.sw?
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: .*.*sw?
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: ].TemporaryItems
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: ].Trashes
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: ].DocumentRevisions-V100
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: ].Trash-*
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: .fseventd
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: .apdisk
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: .htaccess
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: .directory
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: *.part
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: *.filepart
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: *.crdownload
12-07 11:12:45:068 0x7ff591c13eb0 csync_exclude_load: Adding entry: *.kate-swp
12-07 11:12:45:069 0x7ff591c13eb0 csync_exclude_load: Adding entry: *.gnucash.tmp-*
12-07 11:12:45:069 0x7ff591c13eb0 csync_exclude_load: Adding entry: .synkron.*
12-07 11:12:45:069 0x7ff591c13eb0 csync_exclude_load: Adding entry: .sync.ffs_db
12-07 11:12:45:069 0x7ff591c13eb0 csync_exclude_load: Adding entry: .symform
12-07 11:12:45:069 0x7ff591c13eb0 csync_exclude_load: Adding entry: .symform-store
12-07 11:12:45:069 0x7ff591c13eb0 csync_exclude_load: Adding entry: .fuse_hidden*
12-07 11:12:45:069 0x7ff591c13eb0 csync_exclude_load: Adding entry: *.unison
12-07 11:12:45:069 0x7ff591c13eb0 csync_exclude_load: Adding entry: .nfs*
12-07 11:12:45:069 0x7ff591c13eb0 csync_exclude_load: Adding entry: My Saved Places.
12-07 11:12:45:069 3101 OCC::SocketApi::SocketApi: SocketApi: server started, listening at "com.nextcloud.desktopclient.socketApi"
12-07 11:12:45:070 3101 OCC::FolderMan::FolderMan: setting remote poll timer interval to 30000 msec
12-07 11:12:45:070 3101 OCC::AccountManager::restoreFromLegacySettings: Migrate: restoreFromLegacySettings, checking settings group "Nextcloud"
12-07 11:12:45:070 3101 OCC::AccountManager::restoreFromLegacySettings: Migrate: checking old config "/Users/username/Library/Application Support/ownCloud/owncloud.cfg"
12-07 11:12:45:070 3101 OCC::FolderMan::setupFoldersMigration: * Setup folders from "/Users/username/Library/Application Support/Nextcloud/folders" (migration)
12-07 11:12:45:070 3101 OCC::ClientProxy::setupQtProxyFromConfig: Set proxy configuration to use system configuration
12-07 11:12:45:320 3101 unknown: QString::arg: Argument missing: "https://docs.nextcloud.com/desktop/2.2/" , 2
12-07 11:12:45:320 3101 unknown: QString::arg: Argument missing: "https://docs.nextcloud.com/desktop/2.2/" , 3
12-07 11:12:45:416 3101 OCC::ownCloudGui::setupOverlayIcons: Load Finder Overlay-Plugin: "" : 0 ""
12-07 11:12:45:435 3101 OCC::ownCloudGui::slotOpenSettingsDialog: No configured folders yet, starting setup wizard
12-07 11:12:46:314 3101 unknown: QString::arg: Argument missing: "https://docs.nextcloud.com/desktop/2.2/" , 2
12-07 11:12:46:314 3101 unknown: QString::arg: Argument missing: "https://docs.nextcloud.com/desktop/2.2/" , 3
Here is what I found in system console:
07/12/17 11:12:45,322 WindowServer[92]: CGXSetWindowListSystemAlpha: Invalid window 53 (index 0/1)
07/12/17 11:12:46,626 nextcloud_crash_reporter[301]: +[NSGraphicsContext graphicsContextWithCGContext:flipped:]: unrecognized selector sent to class 0x7fff7aace8f8
07/12/17 11:12:46,627 nextcloud_crash_reporter[301]: +[NSGraphicsContext graphicsContextWithCGContext:flipped:]: unrecognized selector sent to class 0x7fff7aace8f8
07/12/17 11:12:46,629 nextcloud_crash_reporter[301]: (
0 CoreFoundation 0x00007fff93a3625c __exceptionPreprocess + 172
1 libobjc.A.dylib 0x00007fff92975e75 objc_exception_throw + 43
2 CoreFoundation 0x00007fff93a3902d +[NSObject(NSObject) doesNotRecognizeSelector:] + 205
3 CoreFoundation 0x00007fff93994272 ___forwarding___ + 1010
4 CoreFoundation 0x00007fff93993df8 _CF_forwarding_prep_0 + 120
5 QtWidgets 0x00000001014e7f43 _ZN23QPixmapDropShadowFilter11qt_metacallEN11QMetaObject4CallEiPPv + 8115
6 QtWidgets 0x00000001014f9708 _ZN23QPixmapDropShadowFilter11qt_metacallEN11QMetaObject4CallEiPPv + 79736
7 QtWidgets 0x00000001011b90a6 _ZNK12QCommonStyle11drawControlEN6QStyle14ControlElementEPK12QStyleOptionP8QPainterPK7QWidget + 1046
8 QtWidgets 0x00000001014f44b2 _ZN23QPixmapDropShadowFilter11qt_metacallEN11QMetaObject4CallEiPPv + 58658
9 QtWidgets 0x00000001012de555 _ZN11QPushButton10paintEventEP11QPaintEvent + 117
10 QtWidgets 0x0000000101173f1d _ZN7QWidget5eventEP6QEvent + 2141
11 QtWidgets 0x000000010123f3af _ZN15QAbstractButton5eventEP6QEvent + 175
12 QtWidgets 0x000000010113bbad _ZN19QApplicationPrivate13notify_helperEP7QObjectP6QEvent + 269
13 QtWidgets 0x000000010113e47c _ZN12QApplication6notifyEP7QObjectP6QEvent + 5852
14 QtCore 0x0000000101f50a24 _ZN16QCoreApplication15notifyInternal2EP7QObjectP6QEvent + 164
15 QtWidgets 0x000000010116d926 _ZN14QWidgetPrivate10drawWidgetEP12QPaintDeviceRK7QRegionRK6QPointiP8QPainterP19QWidgetBackingStore + 3462
16 QtWidgets 0x000000010116e118 _ZN14QWidgetPrivate22paintSiblingsRecursiveEP12QPaintDeviceRK5QListIP7QObjectEiRK7QRegionRK6QPointiP8QPainterP19QWidgetBackingStore + 1192
17 QtWidgets 0x000000010116dfa6 _ZN14QWidgetPrivate22paintSiblingsRecursiveEP12QPaintDeviceRK5QListIP7QObjectEiRK7QRegionRK6QPointiP8QPainterP19QWidgetBackingStore + 822
18 QtWidgets 0x000000010116dfa6 _ZN14QWidgetPrivate22paintSiblingsRecursiveEP12QPaintDeviceRK5QListIP7QObjectEiRK7QRegionRK6QPointiP8QPainterP19QWidgetBackingStore + 822
19 QtWidgets 0x000000010116dba0 _ZN14QWidgetPrivate10drawWidgetEP12QPaintDeviceRK7QRegionRK6QPointiP8QPainterP19QWidgetBackingStore + 4096
20 QtWidgets 0x00000001011491f6 _ZN14QWidgetPrivate10scrollRectERK5QRectii + 8214
21 QtWidgets 0x000000010117414c _ZN7QWidget5eventEP6QEvent + 2700
22 QtWidgets 0x000000010113bbad _ZN19QApplicationPrivate13notify_helperEP7QObjectP6QEvent + 269
23 QtWidgets 0x000000010113e47c _ZN12QApplication6notifyEP7QObjectP6QEvent + 5852
24 QtCore 0x0000000101f50a24 _ZN16QCoreApplication15notifyInternal2EP7QObjectP6QEvent + 164
25 QtCore 0x0000000101f51770 _ZN23QCoreApplicationPrivate16sendPostedEventsEP7QObjectiP11QThreadData + 560
26 libqcocoa.dylib 0x00000001041b219e qt_plugin_instance + 136606
27 libqcocoa.dylib 0x00000001041b2a61 qt_plugin_instance + 138849
28 CoreFoundation 0x00007fff939675b1 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
29 CoreFoundation 0x00007fff93958c62 __CFRunLoopDoSources0 + 242
30 CoreFoundation 0x00007fff939583ef __CFRunLoopRun + 831
31 CoreFoundation 0x00007fff93957e75 CFRunLoopRunSpecific + 309
32 HIToolbox 0x00007fff93657a0d RunCurrentEventLoopInMode + 226
33 HIToolbox 0x00007fff93657685 ReceiveNextEventCommon + 173
34 HIToolbox 0x00007fff936575bc _BlockUntilNextEventMatchingListInModeWithFilter + 65
35 AppKit 0x00007fff8dda524e _DPSNextEvent + 1434
36 AppKit 0x00007fff8dda489b -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] + 122
37 AppKit 0x00007fff8dd9899c -[NSApplication run] + 553
38 libqcocoa.dylib 0x00000001041b191a qt_plugin_instance + 134426
39 QtCore 0x0000000101f4c661 _ZN10QEventLoop4execE6QFlagsINS_17ProcessEventsFlagEE + 401
40 QtCore 0x0000000101f510c9 _ZN16QCoreApplication4execEv + 393
41 nextcloud_crash_reporter 0x00000001010fa443 main + 1139
42 libdyld.dylib 0x00007fff8eb275fd start + 1
)
07/12/17 11:12:47,277 com.apple.IconServicesAgent[245]: main Failed to composit image for binding VariantBinding [0x10f] flags: 0x8 binding: FileInfoBinding [0x20f] - extension: txt, UTI: public.plain-text, fileType: ????.
07/12/17 11:12:47,279 quicklookd[257]: Warning: Cache image returned by the server has size range covering all valid image sizes. Binding: VariantBinding [0x403] flags: 0x8 binding: FileInfoBinding [0x303] - extension: txt, UTI: public.plain-text, fileType: ???? request size:64 scale: 1