And this is the error I have the same problem. I think it might be a GPU problem. Which model of macbook Pro are you using? I personaly use the 2008 model with a patcher for having Catalina and I think that this happens because of the old GPU but if you have a newer model and you also having this problem, something else happens.remoteProcessWasInterruptedError: *** CFRetain() called with NULL ***["DispatchQueueName": com.apple.main-thread, "StackFrameDictionaries": <__NSArrayM 0x600000d5c1e0>({ CrashAnnotationMessage = "*** CFRetain() called with NULL ***"; StackFrameModule = CoreFoundation; StackFramePC = 140734050995199; StackFrameSymbolName = "_CFRetain.cold.1";},{ CrashAnnotationMessage = "*** CFRetain() called with NULL ***"; StackFrameModule = CoreFoundation; StackFramePC = 140734049236914; StackFrameSymbolName = "_CFRetain";},{ StackFrameModule = SceneKit; StackFramePC = 140735062689543; StackFrameSymbolName = "_C3DEngineContextSetRenderContext";},{ StackFrameModule = SceneKit; StackFramePC = 140735063503552; StackFrameSymbolName = "-[SCNRenderer _initWithOptions:isPrivateRenderer:privateRendererOwner:clearsOnDraw:context:renderingAPI:]";},{ StackFrameModule = SceneKit; StackFramePC = 140735064183634; StackFrameSymbolName = "-[SCNView _commonInit:]";},{ StackFrameModule = SceneKit; StackFramePC = 140735064184145; StackFrameSymbolName = "-[SCNView initWithFrame:options:]";},{ StackFrameModule = SceneKit; StackFramePC = 140735064184220; StackFrameSymbolName = "-[SCNView init]";},{ StackFrameFile = "/<compiler-generated>"; StackFrameModule = "Page_LiveView"; StackFramePC = 4584056515; StackFrameSymbolName = "_$sSo7SCNViewCABycfcTO";},{ StackFrameFile = "/<compiler-generated>"; StackFrameModule = "Page_LiveView"; StackFramePC = 4583159311; StackFrameSymbolName = "_$sSo7SCNViewCABycfC";},{ StackFrameFile = "/Users/dazaxer/Library/Mobile Documents/iCloud~com~apple~Playgrounds/Documents/Learn to Code 2.playgroundbook/Contents/Modules/Book.playgroundmodule/Sources/SceneController.swift"; StackFrameLine = 94; StackFrameModule = "Page_LiveView"; StackFramePC = 4583983877; StackFrameSymbolName = "_$s4Book15SceneControllerC5sceneAcA0B0C_tcfc";},{ StackFrameFile = "/Users/dazaxer/Library/Mobile Documents/iCloud~com~apple~Playgrounds/Documents/Learn to Code 2.playgroundbook/Contents/Modules/Book.playgroundmodule/Sources/SceneController.swift"; StackFrameModule = "Page_LiveView"; StackFramePC = 4582976690; StackFrameSymbolName = "_$s4Book15SceneControllerC5sceneAcA0B0C_tcfC";},{ StackFrameFile = "/Users/dazaxer/Library/Mobile Documents/iCloud~com~apple~Playgrounds/Documents/Learn to Code 2.playgroundbook/Contents/Modules/Book.playgroundmodule/Sources/LiveViewConfiguration.swift"; StackFrameLine = 37; StackFrameModule = "Page_LiveView"; StackFramePC = 4582976432; StackFrameSymbolName = "_$s4Book17setUpLiveViewWithyyAA9GridWorldCF";},{ StackFrameFile = "/Users/dazaxer/Library/Mobile Documents/iCloud~com~apple~Playgrounds/Documents/Learn to Code 2.playgroundbook/Contents/Modules/Document13_09.playgroundmodule/Sources/SetUp.swift"; StackFrameLine = 27; StackFrameModule = "Page_LiveView"; StackFramePC = 4584292633; StackFrameSymbolName = "_$s13Document13_0912presentWorldyyF";},{ StackFrameFile = "/Users/dazaxer/Library/Mobile Documents/iCloud~com~apple~Playgrounds/Documents/Learn to Code 2.playgroundbook/Contents/Chapters/Document13.playgroundchapter/Pages/09.playgroundpage/LiveView.swift"; StackFrameLine = 18; StackFrameModule = "Page_LiveView"; StackFramePC = 4582919502; StackFrameSymbolName = "_main";},{ StackFrameModule = ExecutionExtension; StackFramePC = 4493385525;},{ CrashAnnotationMessage = "*** CFRetain() called with NULL ***"; StackFrameModule = CoreFoundation; StackFramePC = 140734049761006; StackFrameSymbolName = "___CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__";},{ CrashAnnotationMessage = "*** CFRetain() called with NULL ***"; StackFrameModule = CoreFoundation; StackFramePC = 140734049760818; StackFrameSymbolName = "___CFRunLoopDoBlocks";},{ CrashAnnotationMessage = "*** CFRetain() called with NULL ***"; StackFrameModule = CoreFoundation; StackFramePC = 140734049756478; StackFrameSymbolName = "___CFRunLoopRun";},{ CrashAnnotationMessage = "*** CFRetain() called with NULL ***"; StackFrameModule = CoreFoundation; StackFramePC = 140734049753891; StackFrameSymbolName = "_CFRunLoopRunSpecific";},{ StackFrameModule = HIToolbox; StackFramePC = 140734028921533; StackFrameSymbolName = "_RunCurrentEventLoopInMode";},{ StackFrameModule = HIToolbox; StackFramePC = 140734028920789; StackFrameSymbolName = "_ReceiveNextEventCommon";},{ StackFrameModule = HIToolbox; StackFramePC = 140734028920185; StackFrameSymbolName = "__BlockUntilNextEventMatchingListInModeWithFilter";},{ StackFrameModule = AppKit; StackFramePC = 140734001966233; StackFrameSymbolName = "__DPSNextEvent";},{ StackFrameModule = AppKit; StackFramePC = 140734001960160; StackFrameSymbolName = "-[NSApplication(NSEvent) _nextEventMatchingEventMask:untilDate:inMode:dequeue:]";},{ StackFrameModule = ViewBridge; StackFramePC = 140734901328462; StackFrameSymbolName = "-[NSViewServiceApplication nextEventMatchingMask:untilDate:inMode:dequeue:]";},{ StackFrameModule = AppKit; StackFramePC = 140734001902062; StackFrameSymbolName = "-[NSApplication run]";},{ StackFrameModule = AppKit; StackFramePC = 140734001713142; StackFrameSymbolName = "_NSApplicationMain";},{ StackFrameModule = AppKit; StackFramePC = 140734004996741; StackFrameSymbolName = "__NSApplicationMainWithInfoDictionary";},{ StackFrameModule = UIKitMacHelper; StackFramePC = 140734873738752; StackFrameSymbolName = "_UINSApplicationMain";},{ StackFrameModule = UIKitCore; StackFramePC = 140735133230847; StackFrameSymbolName = "_UIApplicationMain";},{ StackFrameModule = "libxpc.dylib"; StackFramePC = 140735025314256; StackFrameSymbolName = "__xpc_objc_main.cold.5";},{ StackFrameModule = "libxpc.dylib"; StackFramePC = 140735025243216; StackFrameSymbolName = "__xpc_objc_main";},{ StackFrameModule = "libxpc.dylib"; StackFramePC = 140735025242003; StackFrameSymbolName = "_xpc_main";},{ StackFrameModule = Foundation; StackFramePC = 140734090592079; StackFrameSymbolName = "-[NSXPCListener resume]";},{ StackFrameModule = PlugInKit; StackFramePC = 140734767492811;},{ StackFrameModule = PlugInKit; StackFramePC = 140734767492084;},{ StackFrameModule = PlugInKit; StackFramePC = 140734767493810;},{ StackFrameModule = Foundation; StackFramePC = 140734091086805; StackFrameSymbolName = "_NSExtensionMain";},{ StackFrameModule = "libdyld.dylib"; StackFramePC = 140735022812361; StackFrameSymbolName = "_start";}), "ThreadID": 411889, "ThreadIsMain": 1, "ThreadCrashed": 1]

I have the same problem and I don't know what to do.