I see this error for every instance of my custom component. I set a breakpoint on the browser and evaluated “this” to see the ComponentRegistry state.
As you can see, the warning message is being printed from a ComponentRegistry that has zero elements. But then there is another ComponentRegistry that has the 3 custom components I have rendered.
I’m sure I’m calling only once to Streamlit.setComponentReady() and my components are working as expected. So this seems to be caused by Streamlit having two ComponentRegistry on the main document.