The text "<jsondata-invalidjson>" appears above the HTML textarea on test2.wikipedia.org when attempting to save an invalid JSON Schema.
Steps to reproduce:
- Enter "abc" into the textarea and press "Save page".
- Observe the area above the textarea post-submission. The user ends up at a URL such as https://test2.wikipedia.org/w/index.php?title=Schema:HELLO&action=submit and the top of the page reads:
Creating Schema:HELLO
<jsondata-invalidjson>
Might be localisation cache? Dunno.
Version: unspecified
Severity: normal