Each workspace has a limited capacity of members. The Personal Workspace, for example, has a member capacity of 4. That means it can support up to four devices to sync data at any given time. If your workspace is already at-capacity, then you will not be able to create any more invitations to the workspace.
More on workspace membership
The membership of a workspace is actually tied to databases. So if you have two databases that are all connected to the same workspace, even if they're on the same computer, they would be counted as two devices in your workspace. If you erased your hard drive and reinstalled the OS and Pagico, your Pagico will end up with a new computer ID. When that happens, it'll appear as a new device to the workspace server, therefore requiring yet another spot in your workspace to sync data. So, from time to time, you might end up with redundant device entries in your workspace.
Freeing up your workspace
You can free up your workspace by removing unused / redundant device entries. To do so, simply click on the workspace in question from the sidebar, switch to the Settings tab, and select "Remove" on the unused device entry. Then, click "Save Settings" button to apply the changes. Please note that you'll need to have the Owner's privilege to perform this action. If you do not see the controls to remove devices or to save settings, that means you do not have the Owner's privilege in this workspace.
If you are attempting to re-join your workspace using the Auto-Join feature, but cannot connect to it because the workspace is already at-capacity, you will receive an error message about it. In this case, simply create a support ticket with us, and paste the error message into the ticket message field. We'll be happy to look into your workspace and clear out devices for you as needed.