IOS XOCDE Compile Error NSObjCRuntime.h

Today encountered a relatively rare problem, recorded, to meet the people to answer the following, error prompts as follows:

Everyone should know that runtime is the OC compiled into the bottom of the C, he is here to report this error, we want to first think about whether we have changed this file, if the exclusion of this possibility, we have to think of the project PCH is wrong, and the author's problem is that PCH was wrong.

If the PCH file is modified, the compilation succeeds.

IOS XOCDE Compile Error NSObjCRuntime.h