Jonathan suggest here: Xcode Includes .xib files that have been deleted! that cleaning all targets and empty the caches will fix the problem with Xcode including deleted .xi
I tried almost everything but could not help,what helped me was disabling SIP(System Integration Protection) n it works,I do not know what happens when and how but system file get confused somewhere and causes this...though there might be risks to disabling this obviously
here is how
1.Power on your Mac and hold down the [command]+[R] keys to access the Recovery Partition.
2.From the Recovery Partition, click Utilities from the menu bar, and then select Terminal.
3.Enter the following command into Terminal and press Enter to execute it: csrutil disable
4.Once the command has executed, exit the Terminal and reboot the Mac. When you log back into OS X, SIP will be disabled.