I went back to an old project and recompiled it for OS 4.1 succesfully and ran it. I was asked to add a fourth tab to the Tab Bar, but I could not set its class to the newly added ModelsVC.h/.m. [edit: because it did not appear in the class dropdown, but the other viewcontrollers were there.]
I moved the project folder to a backup folder and unzipped a months old backup of the same project. It compiles and runs until the end of viewWillAppear for the first (default) view connected to the first tab, and then does nothing more. It is still running, but nothing is shown and nothing happens.
In the console, it says “Unknown class ModelsVC in Interface Builder file.”
The problem is, that class didn’t exist two months ago, so why should this way old project complain about it or even know about it?
I’d like to know where to look / tell XCode to use the .xib that is inside the project folder it is currently compiling.
And if it’s path-related, how do I check what paths XCode looks in when a project is loaded/compiled?
Seems a ‘sloppy copy’ for whatever reason (such as a quick backup to try something experimental) of a project folder causes confusion. See this.