This week I bought my first Mac in about 10 years (yeah!). It's a used Mac Pro (2x2GHz Dual-Core Xeon with 2GB RAM). It has a fresh install of Mac OS X Lion 10.7.2. I've only installed OmniOutlner Pro, Textmate, and Ruby RVM.

I've also downloaded and installed Xcode 4.2.1 from the App Store. At first, Xcode worked fine (only launched to see if it worked). Then, the next day I launched Xcode to start using it and it crashed immediately upon launch. Since then, I've tried many things to try to correct the problem: rebooting, reinstalling, redownloading and reinstalling, deleting and reinstalling, deleting iTunes and reinstalling (an early Stack Overflow answer suggested this), and more. Nothing seems to help. Sometimes I can get as far as clicking on a menu item in XCode (while the crash message is being displayed), but that's it.

Everything else seems to work perfect on this machine, so I doubt it's the hardware. I do not have the OS X install DVD.

I bought this system so I can program in Xcode. What would you do if you were me?

---

**UPDTE-1**: Here are the first lines from the Problem Details and System Configuration report (in general it seems most of these I have looked at for this problem seem to be talking about the IDE Navigator Log):

```
Process:         Xcode [17619]
Path:            /Developer/Applications/Xcode.app/Contents/MacOS/Xcode
Identifier:      com.apple.dt.Xcode
Version:         4.2.1 (834)
Build Info:      IDEApplication-834000000000000~2
Code Type:       X86-64 (Native)
Parent Process:  launchd [118]

Date/Time:       2011-12-01 14:33:14.664 -0600
OS Version:      Mac OS X 10.7.2 (11C74)
Report Version:  9

Interval Since Last Report:          72258 sec
Crashes Since Last Report:           5
Per-App Interval Since Last Report:  719 sec
Per-App Crashes Since Last Report:   5
Anonymous UUID:                      1D22E753-40F6-4035-B53A-236881ED2A58

Crashed Thread:  0  Dispatch queue: com.apple.main-thread

Exception Type:  EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000

Application Specific Information:
ProductBuildVersion: 4D502
Encountered multiple assertions. First assertion was: ASSERTION FAILURE in /SourceCache/IDELogNavigator/IDELogNavigator-820/IDELogNavigator.m:582
Details:  (self.rootNavigableItem) should not be nil.
Object:   <IDELogNavigator: 0x4018f6420>
Method:   -revertStateWithDictionary:
Thread:   <NSThread: 0x40010a260>{name = (null), num = 1}
Hints:   
  0: Replacement view is installing: <IDELogNavigator: 0x4018f6420 representing: <DVTExtension 0x400d33120: Log Navigator (Xcode.IDEKit.Navigator.Logs) v0.1>>
Backtrace:
  0  0x00000001055c4366 -[IDEAssertionHandler handleFailureInMethod:object:fileName:lineNumber:messageFormat:arguments:] (in IDEKit)
  1  0x0000000104c3d1a4 _DVTAssertionFailureHandler (in DVTFoundation)
  2  0x000000010ad43cb1 -[IDELogNavigator revertStateWithDictionary:] (in IDELogNavigator)
  3  0x0000000104bffe5b -[DVTStateToken _pullStateFromDictionary:] (in DVTFoundation)
  4  0x0000000104bffc12 -[DVTStateToken pullStateFromRepository] (in DVTFoundation)
  5  0x000000010550f33d -[IDENavigatorArea replacementView:didInstallViewController:] (in IDEKit)
  6  0x0000000104df75f1 __42-[DVTReplacementView _setupViewController]_block_invoke_0 (in DVTKit)
  7  0x0000000104c00f4e DVTInvokeWithFailureHint (in DVTFoundation)
  8  0x0000000104df7473 -[DVTReplacementView _setupViewController] (in DVTKit)
  9  0x0000000104df7345 -[DVTReplacementView installedViewController] (in DVTKit)

```

---

**UPDATE-2:** Bummer. I tried the approach referenced by Michael Dautermann below, but it didn't work. Here's what I typed in Terminal:

```
sudo tmutil disablelocal
sudo /Developer/Library/uninstall-devtools --mode=all
sudo /Developer-old/Library/uninstall-devtools --mode=all
sudo /Developer-old-1/Library/uninstall-devtools --mode=all
sudo tmutil enablelocal

```

At this point, the /Developer, /Developer-old, and /Developer-old-1 folders were deleted. I then emptied the trash and reinstalled XCode. Everything seemed to be going fine, but when I launched XCode, it immediately crashed again :-(

However, three additional bits of information:

1. The Problem Details in the Problem Report when XCode crashes appears to be basically the same as the Problem Details reported above.
2. The version of XCode that gets installed is XCode 4.2.1 Build 4D502, if that matters.
3. I've now noticed that if I hit "Continue" in the Internal Error crash dialog, about 15 times, XCode becomes usable to the point of exploring the menus, etc., and only seems to bring up the Internal Error crash dialog again if I try to quit.

If anyone has any other ideas, I'm open to trying them. I'm starting to wonder if I have a hardware problem somewhere or if I should downgrade to Snow Leopard and XCode 3.