Shows I need C++ addon installed and it is already installed

[mostlyhuman]

I am selecting a function in my code and clicking on SequenceDiagram and it gives this message: "Unsupported (Language: C++) source file. You may need install language extension plugin for SequenceDiagram from Marketplace: e.g. SequenceDiagram Java, SequenceDiagram JS, SequenceDiagram Rust..." Both the main plugin and the C++ plugin are active and trial license shows 28 days remaining. I uninstalled and reinstalled the C++ language plugin but had the same result.