We are sorry for your difficulties as you are unable to invite users and shared libraries. To investigate the issue, could you please let us know the application you use to share libraries, and also do you have a personal or enterprise account? Could you please share a screenshot of the error? Please let us know the Creative Cloud Version and OS version.
We are here to help, it's just we need a little more information.
I attached the error message I have been recieving. I also attached an image of the CC version I have currently. OS is Windows 10 Enterprise 20H2. This is on an enterprise account. There are already 10 people or so who are using these libraries (used the same "invite" function for them too) but, for whatever reason, it is no longer working on some of the libraries.
I've tried sending it using the CC app itself and also the CC website. These libraries are primarily used in InDesign and Illustrator