Why am I getting ibtool failed with exit code 255?

Question

I had something similar happen to me recently using Xcode 4.6 and iOS 6.1.

All I did was switch to a different device version (5.1) on the simulator and it ran. Switched back to 6.1 and it fixed itself.

Xcode can be unhelpful at times.

This happen to us and we clean cache, delete Derived data folder.. etc. nothing happen.

below steps made it fix,

1. open xib(nib) as Source Code (Right click on the xib Open As > Source Code from Xcode or open it using TextEdit)
2. remove this appearanceType="aqua"
3. save and open using Xcode

For more explain use this article, it help us to fix the issue.

Try cleaning the app. Cmd-Shft-K.

Try to find all XIB files in project and open it. One of them will most likely crash your Xcode.

My problem was custom fonts in some XIB file.

I had to install missing fonts on my computer and problem was solved.

1. Restart Xcode - Didn't Work
2. Cleaning the App - Didn't Work
3. Deleting the derivedData - Didn't Work
4. Reset simulator content and settings - Didn't Work
5. changing simulator versions - Didn't Work
6. Restart the OS - Magically Works

I'm not sure which part did the magic and yes it killed a lot of time.