Xcode generates an internal error message

When I try to open my project, I get the message "Internal error". Do you have any idea what is going on?

Xcode has detected an internal logical error. Select Continue to continue running Xcode in an inconsistent state. Select Crash to stop Xcode and report an error with Crash Reporter. Selecting "Crash" will result in the loss of all unsaved data.

and the details are as follows:

ASSERTION FAILURE in /SourceCache/IDEFoundation/IDEFoundation-943/Framework/Classes/Model/Execution/RunContext/IDEBuildSchemeAction.m:912
Details:  (_buildableReference) should not be nil.
Object:   <IDEBuildActionEntry: 0x403120140>
Method:   -dvt_awakeFromXMLUnarchiver:
Thread:   <NSThread: 0x40010a220>{name = (null), num = 1}
Hints:   None
Backtrace:
  0  0x000000010b6a8366 -[IDEAssertionHandler handleFailureInMethod:object:fileName:lineNumber:messageFormat:arguments:] (in IDEKit)
  1  0x000000010ad201a4 _DVTAssertionFailureHandler (in DVTFoundation)
  2  0x000000010b246e89 -[IDEBuildActionEntry dvt_awakeFromXMLUnarchiver:] (in IDEFoundation)
  3  0x000000010ad2585a -[DVTXMLUnarchiver decodeElementNodeWithXMLTextReader:owner:container:parsingState:success:error:] (in DVTFoundation)
  4  0x000000010ace024a -[DVTXMLUnarchiver decodeNodeWithXMLTextReader:owner:container:parsingState:error:] (in DVTFoundation)
  5  0x000000010ad25551 -[DVTXMLUnarchiver decodeElementNodeWithXMLTextReader:owner:container:parsingState:success:error:] (in DVTFoundation)
  6  0x000000010ace024a -[DVTXMLUnarchiver decodeNodeWithXMLTextReader:owner:container:parsingState:error:] (in DVTFoundation)
  7  0x000000010ad25551 -[DVTXMLUnarchiver decodeElementNodeWithXMLTextReader:owner:container:parsingState:success:error:] (in DVTFoundation)
  8  0x000000010ace024a -[DVTXMLUnarchiver decodeNodeWithXMLTextReader:owner:container:parsingState:error:] (in DVTFoundation)
  9  0x000000010ad25551 -[DVTXMLUnarchiver decodeElementNodeWithXMLTextReader:owner:container:parsingState:success:error:] (in DVTFoundation)
 10  0x000000010ace024a -[DVTXMLUnarchiver decodeNodeWithXMLTextReader:owner:container:parsingState:error:] (in DVTFoundation)
 11  0x000000010acdff6a -[DVTXMLUnarchiver _readAndReturnError:] (in DVTFoundation)
 12  0x000000010acdfc84 -[DVTXMLUnarchiver decodeWithRootObject:error:] (in DVTFoundation)
 13  0x000000010b245cc5 +[IDEScheme schemeFromXMLData:withRunContextManager:customDataStoreContainer:customDataSpecifier:isShown:orderHint:error:] (in IDEFoundation)
 14  0x000000010b24542e -[IDERunContextManager _updateMap:contextForCustomDataStore:specifier:] (in IDEFoundation)
 15  0x000000010b244b6f -[IDERunContextManager _customDataStoresDidUpdate] (in IDEFoundation)
 16  0x000000010ad2a9d0 -[NSObject(DVTPropertyLinking) dvt_addObserverWithName:toKeyPath:ofObject:block:] (in DVTFoundation)
 17  0x000000010b244554 -[IDERunContextManager initWithWorkspace:] (in IDEFoundation)
 18  0x000000010b2441e5 -[IDEWorkspace _setupRunContextManager] (in IDEFoundation)
 19  0x000000010b29e02e __81-[IDEWorkspace _finishLoadingAsynchronously:shouldUpgradeFromSimpleFilesFocused:]_block_invoke_0 (in IDEFoundation)
 20  0x00007fff8d9a3b05 -[NSBlockOperation main] (in Foundation)
 21  0x00007fff8d96a6d8 -[__NSOperationInternal start] (in Foundation)
 22  0x00007fff8d97d936 ____NSOQSchedule_block_invoke_2 (in Foundation)
 23  0x00007fff81bde8ba _dispatch_call_block_and_release (in libdispatch.dylib)
 24  0x00007fff81be072a _dispatch_main_queue_callback_4CF (in libdispatch.dylib)
 25  0x00007fff81f3506c __CFRunLoopRun (in CoreFoundation)
 26  0x00007fff81f34676 CFRunLoopRunSpecific (in CoreFoundation)
 27  0x00007fff87a8231f RunCurrentEventLoopInMode (in HIToolbox)
 28  0x00007fff87a895c9 ReceiveNextEventCommon (in HIToolbox)
 29  0x00007fff87a89456 BlockUntilNextEventMatchingListInMode (in HIToolbox)
 30  0x00007fff86c93f5d _DPSNextEvent (in AppKit)
 31  0x00007fff86c93861 -[NSApplication nextEventMatchingMask:untilDate:inMode:dequeue:] (in AppKit)
 32  0x00007fff86c9019d -[NSApplication run] (in AppKit)
 33  0x00007fff86f0eb88 NSApplicationMain (in AppKit)
 34  0x000000010acb3eec (in Xcode)
 35  0x0000000000000002