Visual editor buttons disappear

Bug symptom: The buttons of the visual editor disappear in the edit page view, when the plugin is enabled (version 1.0b3).

Javascript error: "Failed to load: undefined/langs/en.js"

Offending line of code: /shrimptest/plugins/variant-shortcode/tinymce.js, line 2, which is tinymce.PluginManager.requireLangPack('variant_shortcode');

Temporary fix: Commenting out that line fixes the problem.