In xcode4, (I have used v4.0.1 until now and downloaded v4.0.2 yesterday.) I made Localizable.string files and compiled my project. (As you know, my source code uses NSLocal
With Xcode 10.1, one missing semicolon stops compilation with this error:
Localizable.strings: read failed: Couldn't parse property list because the input data was in an invalid format
BTW, you can find out if the error is general to your file (an encoding issue) or specific to one or more lines by temporarily removing most of the file content. You can then locate the problem by incrementally adding content back in until the error returns.