Same issue on our site after latest update to the plugin.
Also happened on my site after update
This comes from your site running PHP 5.2 – I am working on a fix to make this backward compatible to PHP 5.2 this weekend. In the meantime please revert to version 1.3. Let me know if http://downloads.wordpress.org/plugin/widget-builder.1.3.zip does not work for you and I can send you a copy of my local repo reverted to v1.3.
I have released version 1.5 this resolves issues with PHP 5.2 compatibility. You may download automatically from the .org repo or manually replace your installation with the download from http://downloads.wordpress.org/plugin/widget-builder.1.5.zip . Please let me know if you continue to have any issues.
@timothy: V1.5 works. Thank you so much.
I’m glad this helped you out! If you don’t mind selecting “Works” for your version of WP/Plugin in order to let folks know the support data.