The entire editor disappears when I try to add a package

Whenever I try to add package by clicking on the “Add Package” button, the entire editor disappears then goes into a fully blank page.
I inspected the element of the Glitch editor, and it seems like the button basically removes the division inside of the following code:

<div id="__react-app-root"></div>

Please I need to edit this project, it’s not really allowing me to use the editor ;-; (Although you could still add package by typing, but the package.json just really seem to be glitchy for no reason.