Qsys component editor: No modules found when analyzing null

I have had the same problem in QSYS, it is very irritating. I have been working around it by doing the HDL analysis at the command line. This allows you to check a single file at a time but at least gives some decent output that helps find the syntax errors.

quartus_map <project_name> --analyze_file=<filename and path>

This will find syntax errors.

Note that you don't actually need an active project to run this command. You can just fill project name with any text, it just needs something, it will create a base project for you.

Once you have a base project you can re-run the command without the --analyze_file hook to do basic synthesis analysis.