我在运行xcode项目时遇到这个问题。我会启动这个项目，模拟器会加载，但一旦加载了应用程序，我就会让它崩溃。这是错误代码：线程1:异常："；无法将标识符为ChecklistItem的单元格出列-必须为该标识符注册一个nib或类，或者在情节提要中连接一个原型单元格"；并在终端上说：
2020-07-24 18:11:06.757164+0100 Checklists[983:49709] *** Assertion failure in -[UITableView _dequeueReusableCellWithIdentifier:forIndexPath:usingPresentationValues:], /Library/Caches/com.apple.xbs/Sources/UIKitCore_Sim/UIKit-3920.31.102/UITableView.m:8724
2020-07-24 18:11:06.771044+0100 Checklists[983:49709] *** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'unable to dequeue a cell with identifier ChecklistItem - must register a nib or a class for the identifier or connect a prototype cell in a storyboard'
*** First throw call stack:
(
0 CoreFoundation 0x000000010b93ae6e __exceptionPreprocess + 350
1 libobjc.A.dylib 0x000000010a23a9b2 objc_exception_throw + 48
2 CoreFoundation 0x000000010b93abe8 +[NSException raise:format:arguments:] + 88
3 Foundation 0x0000000109c1bbd2 -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 191
4 UIKitCore 0x000000010e53d6be -[UITableView _dequeueReusableCellWithIdentifier:forIndexPath:usingPresentationValues:] + 1332
5 UIKitCore 0x000000010e53d156 -[UITableView dequeueReusableCellWithIdentifier:forIndexPath:] + 91
6 Checklists 0x0000000109979a38 $s10Checklists23ChecklistViewControllerC05tableC0_12cellForRowAtSo07UITableC4CellCSo0jC0C_10Foundation9IndexPathVtF + 264
7 Checklists 0x0000000109979b25 $s10Checklists23ChecklistViewControllerC05tableC0_12cellForRowAtSo07UITableC4CellCSo0jC0C_10Foundation9IndexPathVtFTo + 165
8 UIKitCore 0x000000010e556e96 -[UITableView _createPreparedCellForGlobalRow:withIndexPath:willDisplay:] + 867
9 UIKitCore 0x000000010e520522 -[UITableView _updateVisibleCellsNow:] + 3010
10 UIKitCore 0x000000010e54024e -[UITableView layoutSubviews] + 194
11 UIKitCore 0x000000010e8465f4 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 2478
12 QuartzCore 0x00000001103b1260 -[CALayer layoutSublayers] + 255
13 QuartzCore 0x00000001103b73eb _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 523
14 QuartzCore 0x00000001103c2a8a _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 80
15 QuartzCore 0x000000011030ba7c _ZN2CA7Context18commit_transactionEPNS_11TransactionEd + 324
16 QuartzCore 0x000000011033f467 _ZN2CA11Transaction6commitEv + 649
17 UIKitCore 0x000000010e3566c3 __34-[UIApplication _firstCommitBlock]_block_invoke_2 + 81
18 CoreFoundation 0x000000010b89eabc __CFRUNLOOP_IS_CALLING_OUT_TO_A_BLOCK__ + 12
19 CoreFoundation 0x000000010b89e1b3 __CFRunLoopDoBlocks + 195
20 CoreFoundation 0x000000010b898fa3 __CFRunLoopRun + 995
21 CoreFoundation 0x000000010b8988a4 CFRunLoopRunSpecific + 404
22 GraphicsServices 0x0000000114910bbe GSEventRunModal + 139
23 UIKitCore 0x000000010e33e968 UIApplicationMain + 1605
24 Checklists 0x000000010997aa1b main + 75
25 libdyld.dylib 0x000000010c8581fd start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)
根据错误，您在设置表视图时没有注册单元格。
检查文档：
tableView.register(UITableViewCell.self, forCellReuseIdentifier: "DefaultCell")
或
tableView.register(UINib(nibName: "yourNib", bundle: nil), forCellReuseIdentifier: "CellFromNib")
只需填写cell、nibName、identifier等的正确值……取决于使用的方法
如果你需要更多信息，这里有一个指南链接：链接