Good day
We are using the premium plan and have shared our notebooks to some people; however from once in a while the people we shared with get a message that they should upgrade to premium because there is not enough space to add documents, sometimes the content in the notebook is really small and others who have much more content aren't experiencing this problem.
We would just give it time and soon after they are able to add their documents on the notebook we shared but it's a problem we face often and want to deal with it effectively.
