I'm not sure if this is a Scribunto problem or a something else problem, but I tried to use Special:Import to move a module from test2wiki, and I got the following error:
Import failed: No handler for model 'Scribunto'' registered in $wgContentHandlers
My test settings were:
comment: test import.
No entry is created in the import log. However, a broken page is created at the destination saying:
The revision #0 of the page named "Headnote" does not exist.
</p><p>This is usually caused by following an outdated history link to a page that has been deleted.
Details can be found in the <a class="external text" href="//en.wikipedia.org/w/index.php?title=Special:Log/delete&page=Module:Headnote">deletion log</a>.
And it won't let one save anything to the page, instead giving a bogus edit conflict that can't be resolved. The broken page can be removed using page deletion.
The import log does show that some Module pages were imported previously (abotu two weeks ago), so maybe this is a recent problem, or maybe my specific request is triggering it in some way.