The same holds when a Html5 movie is generated and rendered perfectly as cell output [HTML(*)].
When the file is saved and reopened again the cell output seems to be gone, but it is not.
Just “trusting” the notebook renders the cell again.
I understand this is due to a lack of trust in html code.
Could the blocked rendering of HTML output in an existing file not be replace by a small message:
“HTML output not rendered, as this notebook is not trusted. Please trust the notebook to render this cell”?
This would prevent me from rerunning cells unneeded, as some of these movie calculations can take a lot of time.