It’s entirely possible that it is a problem with matrix, or some other addon I’m using. BUT…
In my Matrix (below) I’ll use SC File and it generates the following error on screen (and the following in code view as well).
If I switch back to the normal EE file field, the errors and problems disappear.
In the “code” screenshot, it seems that after the SC File settings (script), a closing script tag is issued, and then breaks the rest of the matrix.
Thanks!
Images below.