iOS Question App Crash after B4i Update


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After updating to the latest B4i, my App is now crashing on startup.

This is the error:
Error occurred on line: 172 (Main)
Error opening stream (/private/var/mobile/Containers/Data/Application/486CA0FC-72B3-4871-8471-5C3DAC242626/tmp/virtual_assets/rootpanel.bil): Error Domain=NSPOSIXErrorDomain Code=2 "No such file or directory" UserInfo={_kCFStreamErrorCodeKey=2, _kCFStreamErrorDomainKey=1}
Stack Trace: (
  CoreFoundation       <redacted> + 252
  libobjc.A.dylib      objc_exception_throw + 56
  CoreFoundation       <redacted> + 0
  MD Football          -[B4IFile OpenInput::] + 440
  MD Football          -[B4ILayoutBuilder loadLayout:::] + 652
  MD Football          -[B4IPanelWrapper LoadLayout::] + 204
  MD Football          -[b4i_main _application_start:] + 1144
  CoreFoundation       <redacted> + 144
  CoreFoundation       <redacted> + 292
  MD Football          +[B4I runDynamicMethod:method:throwErrorIfMissing:args:] + 1624
 MD Football          -[B4IShell runMethod:] + 448
 MD Football          -[B4IShell raiseEventImpl:method:args::] + 2172
 MD Football          -[B4IShellBI raiseEvent:event:params:] + 1580
 MD Football          __33-[B4I raiseUIEvent:event:params:]_block_invoke + 60
 libdispatch.dylib    <redacted> + 24
 libdispatch.dylib    <redacted> + 16
 libdispatch.dylib    <redacted> + 1068
 CoreFoundation       <redacted> + 12
 CoreFoundation       <redacted> + 1924
 CoreFoundation       CFRunLoopRunSpecific + 436
 GraphicsServices     GSEventRunModal + 104
 UIKitCore            UIApplicationMain + 212
 MD Football          main + 124
 libdyld.dylib        <redacted> + 4

This line:

This app was working fine before. I added some additional code, but I have not changed the layouts at all.

any ideas?

Edit: Works fine in release mode. Its a Debug mode bug.
Last edited:


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Rolling back didnt fix it, so something else happened.

I couldnt figure it out, so I uninstalled the App completely from my iPad and let it reinstall the debug version, Then it worked again.

Cause? Unknown.
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I don't use B4i, but I do intermittently have similar issues with apps I've developed in Xcode / Swift. Every so often one of them will crash on startup with no errors & the only way I can get it to work again is to reinstall it. I don't know if it's because of an iOS update or possibly an SDK update & I never see an error so it's quite odd.

- Colin.
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