Xcode "Use of undeclared identifier" errors, compiles/runs just fine

I was having the same problem and noticed that all of the undeclared identifiers were declared in files that were in my pch file.

With this in mind I deleted one of the #import lines from the pch file and recompiled which failed as expected. I then put the deleted line back in, recompiled and it compiled normally with all the false errors gone.

Hopefully this simple solution helps a few of you out if the above solutions don't.

These kinds of errors are quite common with Xcode, unfortunately. It would be great if it would auto-refresh its error list all the time, but it doesn't always. When this happens, I strongly suggest that you restart Xcode, which will flush its error cache and hopefully solve your issues.

How are you including this class? In most cases I just include the class explicitly in header and/or body - instead of the *.pch file. Then this error goes away in my case.

Also deleting the derived data workes once in a while. Did you change the location in preferences recently by any chance. I also got this error when I use a ramdisk for derived data and then go back to default. This is the most annoying case - since it causes this error to appear then in almost every file.

This error seems to happen more often in Xcode 4.4 than the prior versions.