Objective-C : getting error on console while trying to display app on ipad device?

I am trying to display my iphone/Ipad app on my iPad but getting this error, I checked this app on device earlier but now its giving error on console.

**warning: Unable to read symbols for /Developer/Platforms/iPhoneOS.platform/DeviceSupport/4.2.1 (8C148)/Symbols/usr/lib/info/dns.so (file not found).**

**Couldn't register com.domainname.abcdef with the bootstrap server. Error: unknown error code.

This generally means that another instance of this process was already running or is hung in the debugger.Program received signal: “SIGABRT”.

warning: Unable to read symbols for /Developer/Platforms/iPhoneOS.platfo开发者_开发技巧rm/DeviceSupport/4.2.1 (8C148)/Symbols/Developer/usr/lib/libXcodeDebuggerSupport.dylib (file not found).**

My application working fine on Simulator but giving this error on device provided that yesterday it was also working on device with same code.

I restarted Xcode , deleted build folder but no succes.

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I just restarted the device and deleted the build folder and not its working ...

but I think it could working just by restarting the device ...

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Plz do as following...

Restart iOS Simulator and then Reset contents and settings and then delete build folder from directory path and then clean all targets after this run your application...

I am not sure about this but when i got this error I had done the same thing and solved this error..

Remove your device and connect it again.. and restart XCode and then try again..

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Restarting Xcode will surely resolve this error....