We tried to make OpenKM as intuitive as possible, but an advice is always welcome.
Forum rules: Please, before asking something see the documentation wiki or use the search feature of the forum. And remember we don't have a crystal ball or mental readers, so if you post about an issue tell us which OpenKM are you using and also the browser and operating system version. For more info read How to Report Bugs Effectively.
Subscription to a document needs you got write grants ( is something we've got on discussion several times ). At the present without write grant you can not subscribe to a document, folder etc... We've been considered document attribute and without write grants we do not allow any change. We can reconsiderate it, because subscription seems something not much hard linked than creation date among other attributes. Here - openkm staff- we've not been able to get consens on it.