Why am I getting ibtool failed with exit code 255?

Question

All of a sudden I can\'t build my project. I get the following compiler error:

/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.pl

Answer 1

I was getting this error when building for 10.9 an .XIB that was created in XCode 6.4 (10.10).

See this answer. The XIB was calling for 'labelColor' which was introduced in 10.10, and was unknown to 10.9.

Opening the XIB as source kept it from crashing XCode, and permitted me to change instances of 'labelColor' to 'textColor' and the error was resolved.