as I already told you on slack every content-driven platform can be really affected of this problem.
It would be fantastic to have more informations about the kind of platform, the target users, industry, etc..
In any case, some general rules are:
1) Provide additional informations when you already don't have any content. You can think to add links to similar resources that you already have.
2) Prepare the user to be a player of your platform. This is a general rule to improve the engagement. If the users will be in charge of upload informations, lead the way to do that ... making them aware that the platform will become better and better thanks to their help.
3) Design in a good way your information. Try to avoid as much as possible folders with 0 informations on the top of your navigation / first level of navigation. Group by categories but being flexible with the quantity of information that you have. If it is possible avoid the standard hierarchy.
Feel free to ask you more informations