Hi, please let me start again. The plugin does not create folders, it’s WordPress that creates the plugin folder and expands the package files inside it. So there should no permission problems. But it seems some urls are protected in your site.
Hence: can we start again from a subscription box which I can test, to try to track down again the problem?
I´m not using the plugin due to this problem, i dont know if it always be since i have installed the plugin or its since i have moved to a dedicated server, i have never tested the unsuscription form by myself.