Warning about translation

Hi,
I did update to WP 3.5 and I don’t know if it’s because of this but now my weather widget is displaying:

Warning: Illegal offset type in isset or empty in /***/wp-includes/pomo/translations.php on line 72

https://screencast.com/t/QiSvfALwEQN

I built the website in japanese and wp is localized in japanese as well.

What does it mean? Is there a workaround or quick fix for this otherwise I can’t use your plugin anymore

https://www.ads-software.com/extend/plugins/world-weather-wwo/