我对 xcode 有疑问。我从事过iphone项目并正常打开它。但是今天我无法打开它。当我尝试打开它时，xcode 崩溃并显示日志：
ASSERTION FAILURE in /SourceCache/IDEFoundation/IDEFoundation-937/Framework/Classes/Model/Logging/ActivityLog/IDEActivityLogSection.m:771
Details: Assertion failed: nBytesRead <= sizeof(buffer)
Object: <IDEActivityLogSection>
Method: +sectionWithContentsOfFile:error:
Thread: <NSThread: 0x200025720>{name = (null), num = 1}
Hints: None
Backtrace:
0 0x00000001009e6646 -[IDEAssertionHandler handleFailureInMethod:object:fileName:lineNumber:messageFormat:arguments:] (in IDEKit)
1 0x000000010006aaa4 _DVTAssertionFailureHandler (in DVTFoundation)
2 0x000000010061a094 +[IDEActivityLogSection sectionWithContentsOfFile:error:] (in IDEFoundation)
3 0x000000010057b84d -[IDEOnDiskActivityLogRecord fullLogWithError:] (in IDEFoundation)
4 0x00000001006bad4b __79-[IDEOnDiskActivityLogRecord initWithUUID:store:cacheEntry:updatedCache:error:]_block_invoke_0 (in IDEFoundation)
5 0x00000001006bac48 -[IDEOnDiskActivityLogRecord initWithUUID:store:cacheEntry:updatedCache:error:] (in IDEFoundation)
6 0x000000010057b46c __60-[IDEOnDiskLogStore_Impl initWithRootDirectoryAtPath:error:]_block_invoke_0 (in IDEFoundation)
7 0x00007fff87e5a4da __NSDictionaryEnumerate (in CoreFoundation)
8 0x000000010057b256 -[IDEOnDiskLogStore_Impl initWithRootDirectoryAtPath:error:] (in IDEFoundation)
9 0x0000000100579cf9 +[IDEOnDiskLogStore onDiskStoreInWorkspaceArena:atSubPath:error:] (in IDEFoundation)
10 0x0000000100579bcb +[IDELogStore onDiskOrInMemoryLogStoreInWorkspaceArena:prefix:] (in IDEFoundation)
11 0x0000000100579aaa -[IDEExecutionEnvironment initWithWorkspaceArena:] (in IDEFoundation)
12 0x0000000100579863 -[IDEWorkspace _setupExecutionEnvironment] (in IDEFoundation)
13 0x00000001005e10f4 -[IDEWorkspace _setupWorkspaceArenaIfNeeded] (in IDEFoundation)
14 0x00000001005e13fe __81-[IDEWorkspace _finishLoadingAsynchronously:shouldUpgradeFromSimpleFilesFocused:]_block_invoke_0 (in IDEFoundation)
15 0x00007fff83e8290d -[NSBlockOperation main] (in Foundation)
16 0x00007fff83e72dd0 -[__NSOperationInternal start] (in Foundation)
17 0x00007fff83f50bd5 ____NSOQSchedule_block_invoke_2 (in Foundation)
18 0x00007fff88698d64 _dispatch_call_block_and_release (in libSystem.B.dylib)
19 0x00007fff886778d2 _dispatch_queue_drain (in libSystem.B.dylib)
20 0x00007fff8867817f _dispatch_queue_serial_drain_till_empty (in libSystem.B.dylib)
21 0x00007fff886aaf1c _dispatch_main_queue_callback_4CF (in libSystem.B.dylib)
22 0x00007fff87df4c60 __CFRunLoopRun (in CoreFoundation)
23 0x00007fff87df3d8f CFRunLoopRunSpecific (in CoreFoundation)
24 0x00007fff89b937ee RunCurrentEventLoopInMode (in HIToolbox)
25 0x00007fff89b935f3 ReceiveNextEventCommon (in HIToolbox)
26 0x00007fff89b934ac BlockUntilNextEventMatchingListInMode (in HIToolbox)
27 0x00007fff83481eb2 _DPSNextEvent (in AppKit)
28 0x00007fff83481801 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] (in AppKit)
29 0x00007fff8344768f -[NSApplication run] (in AppKit)
30 0x00007fff834403b0 NSApplicationMain (in AppKit)
31 0x0000000100000eec
请帮我解决这个问题。代码 4.2