To reproduce:
- Edit a page (using the wikitext editor, I don't know about VE)
- Enter {{Special:NewImages}}
- Preview the page
- Observe an error "Widget not found: mw-input-start" in the browser's console.
This seems to have been caused by rMW3a7ce3d629ff: Date range filtering in Special:NewFiles, which caused Special:NewImages to add a RL module for affecting the special page's form without guarding it in if ( !$this->including() ) {.