How to get Zend Studio to recognize and autocomplete functions in the global scope?

Zend Studio underlines existing function names with yellow squiggly lines, even when I explicitly include a file that contains declaration of those functions.

Example:

It used to not do that and I was able to go to the function declaration names by right-click => Open Declaration. Now I can't. I do not know what had changed, it's just that one day those functions became underlined.

How can I enable/configure/restore this feature?

So far I have refreshed project, re-indexed project, re-imported the project, re-added file with function declarations hoping that will update the function database, included file with declarations explicitly. I disabled and re-enabled PHP Semantic Analysis. None of those worked so far.

From top-level menu, go to

• Project
• Properties
• PHP
• Include Path
• Source
• Add Folder

Add folders where your source functions are, press OK, wait for project DLTK indexing to rebuild. Voila!, no more squiggly lines and autocomplete works.

Even after the above worked, I still began to have other issues with my IDE, so what I did I completely uninstalled it, then reinstalled it, and re-created my workspace and re-downloaded my project from GitHub, and now things are back to normal. I will have to reset my project-specific and Zend Studio and other settings though.