This appears to apply to all versions of the app.
<p><span class="error" style="display:none">HIDDEN ERROR: Usage of "past names and nick names" is not recognized</span></p>
Thanks. I'm not sure if something changed in a Scribunto module or somewhere in extension land, but it doesn't seem like it's really turning up on enwiki source, at least - there are some Village Pump discussions on this.
This happens when a template usage triggers a template’s https://en.wikipedia.org/wiki/Module:Check_for_unknown_parameters checks.
As these tend to get cleaned up eventually, its likely this is indeed a temporary effect.