I am struggling with Marketo landing pages being set in the 'template' it originally used, with pre-defined Elements/Variables/Dynamic Content.
Does your landing page have to stick exactly within the templates original sections/set up? Using the template pulls from it's original format so editing this after I have entered my content onto the landing page does nothing.
And how can I get a button variable link to open in a new window? It's set up means I can't edit the code to add in the target=blank code.
Something doesn't sound right. The Module or Element should be editable unless the original coder of the Template made it not editable.
You may need to adjust the Template slightly.
Have you recently enabled SSL for you Marketo instance? If yes, you would need to fix all the "http" reference to 'https'. SSL enablement may affect your landing page and email templates.