Intellij "go to > implementation/declaration" navigation feature not working

Solution 1:

Right click on the root folder of your project (Application code folder) and

select -> Mark Directory as -> Sources root

Solution 2:

This is way too broad of a inquiry!

There's a few things that could be wrong but compiling and running has nothing to do with it. Compilers such as maven can generate sources or modify behaviors of compilation units and can be considered non-deterministic programming which because of its very essence, can't be analyzed.

You're referring to a Contextual IntelliSense operation; in the context you're in currently, dependencies etc may not be properly configured. You can't know what you don't know; similarly, Intellij can't either. Make sure all libraries are listed properly within the Project/Global -> Libraries section in order to have them properly function.

Alternatively, your cache could have become corrupted. Try File -> Invalidate Caches / Restart...

Lastly you could simply have the option disabled somehow. There's various settings which will disable the option. For example, Power Save Mode may be enabled. For the rest I suppose it'd be best to refer you to the help documentation.

Solution 3:

It seems that the index is wrong.You need to force reindex the project files. Just try: File -> Invalidate caches... Then restart your IntelliJ