Sorry, I just noticed that the Crashes column was set to Last Year. When I set it to Last Two Weeks, I get the data.

Same for Xcode 11.5.I just started having this problem today, but only with one project. I tried opening Xcode while holding down Shift as suggested, but that had no effect. I also tried reloading the xcode.project from a recent backup, no joy. Apple really needs to address this problem! Here is the log.Process: Xcode [5780]Path: /Applications/Xcode.app/Contents/MacOS/XcodeIdentifier: com.apple.dt.XcodeVersion: 11.5 (16139)Build Info: IDEFrameworks-16139000000000000~62 (11E608c)App Item ID: 497799835App External ID: 835814967Code Type: X86-64 (Native)Parent Process: ??? [1]Responsible: Xcode [5780]User ID: 503Date/Time: 2020-06-09 15:08:18.920 -0500OS Version: Mac OS X 10.15.4 (19E287)Report Version: 12Anonymous UUID: 79A51667-E346-704F-A7E9-60A204A762E4Time Awake Since Boot: 3400 secondsSystem Integrity Protection: enabledCrashed Thread: 0 Dispatch queue: com.apple.main-threadException Type: EXC_CRASH (SIGABRT)Exception Codes: 0x0000000000000000, 0x0000000000000000Exception Note: EXC_CORPSE_NOTIFYApplication Specific Information:ProductBuildVersion: 11E608cASSERTION FAILURE in /Library/Caches/com.apple.xbs/Sources/IDEFrameworks/IDEFrameworks-16139/IDEKit/Behaviors/Alerts/ShowEditorAlert/IDEShowEditorAlert.m:143Details: Assertion failed: [editorArea _canAddEditorAreaSplitAfterEditorAreaSplit:lastActiveEditorAreaSplit layout:IDEEditorMultipleSplitRelativeLayout_Default]Object: <IDEShowEditorAlert>Method: +_createEditorAreaSplitForEditorArea:lastActiveEditorAreaSplit:Thread: <NSThread: 0x7f9860c1aa60>{number = 1, name = main}Open FDs: 53/9472Hints: Backtrace: 0 -[IDEAssertionHandler handleFailureInMethod:object:fileName:lineNumber:assertionSignature:messageFormat:arguments:] (in IDEKit) 1 _DVTAssertionHandler (in DVTFoundation) 2 _DVTAssertionFailureHandler (in DVTFoundation) 3 _DVTAssertionFailureHandler (in DVTFoundation) 4 +[IDEShowEditorAlert _createEditorAreaSplitForEditorArea:lastActiveEditorAreaSplit:] (in IDEKit) 5 +[IDEShowEditorAlert _editorAreaSplitForDestination:workspaceTabController:] (in IDEKit) 6 -[IDEShowEditorAlert runForEvent:inWorkspace:context:completionBlock:] (in IDEKit) 7 -[IDEAlertEvent runInWorkspace:context:completionBlock:] (in IDEFoundation) 8 -[IDEAlertEvent runInWorkspace:context:] (in IDEFoundation) 9 -[IDEBuildAlertMonitor buildDidStartForExecutionEnvironment:] (in IDEKit)10 __55-[IDEBuildAlertMonitor initWithWorkspaceTabController:]_block_invoke.29 (in IDEKit)11 -[DVTObservingBlockToken observeValueForKeyPath:ofObject:change:context:] (in DVTFoundation)12 NSKeyValueNotifyObserver (in Foundation)13 NSKeyValueDidChange (in Foundation)14 NSKeyValueDidChangeWithPerThreadPendingNotifications (in Foundation)15 -[IDEExecutionEnvironment observeValueForKeyPath:ofObject:change:context:] (in IDEFoundation)16 NSKeyValueNotifyObserver (in Foundation)17 NSKeyValueDidChange (in Foundation)18 -[NSObject(NSKeyValueObservingPrivate) _changeValueForKeys:count:maybeOldValuesDict:maybeNewValuesDict:usingBlock:] (in Foundation)19 -[NSObject(NSKeyValueObservingPrivate) _changeValueForKey:key:key:usingBlock:] (in Foundation)20 _NSSetLongLongValueAndNotify (in Foundation)21 -[IDEBuildOperation start] (in IDEFoundation)22 __NSThreadPerformPerform (in Foundation)23 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ (in CoreFoundation)24 __CFRunLoopDoSource0 (in CoreFoundation)25 __CFRunLoopDoSources0 (in CoreFoundation)26 __CFRunLoopRun (in CoreFoundation)27 CFRunLoopRunSpecific (in CoreFoundation)28 RunCurrentEventLoopInMode (in HIToolbox)29 ReceiveNextEventCommon (in HIToolbox)30 _BlockUntilNextEventMatchingListInModeWithFilter (in HIToolbox)31 _DPSNextEvent (in AppKit)32 -[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:] (in AppKit)33 -[DVTApplication nextEventMatchingMask:untilDate:inMode:dequeue:] (in DVTKit)34 -[NSApplication run] (in AppKit)35 NSApplicationMain (in AppKit)36 main (in Xcode)37 start (in libdyld.dylib)abort() called