Why Xcode does not display app storyboard?

Question

I have an issue with a storyboard in Xcode 12.4 My storyboard is not displayed correctly

I tried these steps:

• restart Xcode
• restart macOS
• clean Deriver data
• cmnd + shift + k
• change device

Error Log:

Encountered an error communicating with IBAgent-iOS. (Failure reason: IBAgent-iOS (-1) failed to launch): Failed to launch IBAgent-iOS via CoreSimulator spawn (Failure reason: Failed to spawn IBAgent-iOS on iPhone 12 Pro Max (FF7523FB-FD48-40DF-9429-0C24F7EF6A64, iOS 14.4, Booted)): Invalid device state

Error Domain=com.apple.InterfaceBuilder Code=-1 "Encountered an error communicating with IBAgent-iOS." UserInfo={NSLocalizedFailureReason=IBAgent-iOS (-1) failed to launch, NSUnderlyingError=0x7fe409786840 {Error Domain=com.apple.CoreSimulator.SimError Code=405 "Failed to launch IBAgent-iOS via CoreSimulator spawn" UserInfo={NSLocalizedFailureReason=Failed to spawn IBAgent-iOS on iPhone 12 Pro Max (FF7523FB-FD48-40DF-9429-0C24F7EF6A64, iOS 14.4, Booted), NSLocalizedDescription=Failed to launch IBAgent-iOS via CoreSimulator spawn, NSUnderlyingError=0x7fe3dc535660 {Error Domain=com.apple.CoreSimulator.SimError Code=405 "Invalid device state" UserInfo={NSLocalizedDescription=Invalid device state}}}}, NSLocalizedRecoverySuggestion=Please check Console.app for crash reports for "IBAgent-iOS" for further information., NSLocalizedDescription=Encountered an error communicating with IBAgent-iOS.}

Thank you for your answers:)

Answer 1

Hey Ekaterina and Welcome to Stackoverflow.

You need a clean reinstallation:

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1. Backup your project and delete XCode from Applications Folder and Empty Trash.

2. Then navigate to /Library and take a look to your Developer Folder. Delete CoreSimulator, XCode, XCTestDevices Folder. Empty trash again.

3. Navigate to /Library/Cahes and look for folder com.apple.dt.XCode and delete the whole folder. Empty trash a last time.

4. Then Restart your Mac/Macbook and go to AppStore and download and reinstall XCode.

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Then it should be all fine.