I would guess it's the (Context.GetContent()).template
that breaks somehow and I assume GetContent
is a custom extension method.
The exception {"No node exists with id '0'"}
usually means that you couldn't fetch the node you requested.
Instead try
else if(new umbraco.cms.businesslogic.template.Template(umbraco.uQuery.GetCurrentNode().template).Alias == "TemplateLanguage")
If that doesn't work it means you are running the code in a context where the CurrentNode is unavailable. In that case you must extend your LoadData method with a nodeId parameter.