Steps to replicate the issue (include links if applicable):

• Navigate to a long page, such as List of nominees for the Nobel Prize in Physiology or Medicine, using the Wikipedia app for Android
• Select "Edit article"
• Make any change
• Select "Next"

What happens?: The app displays the following:

Pretty-print: [unselected checkbox]
{"status":413,"type":"Internal error"}

What should have happened instead?: The app should have displayed a preview of the edited article.

Other information (browser name/version, screenshots, etc.): Wikipedia app for Android, version r/2.7.50540-r-2025-07-08