You are running your account on more than one computer. However, on one of these computers, the account seems to have stopped synchronizing updates. For example, when you add or change content on this computer, the updates do not get sent to your other computer or to other members of your workspaces. Similarly, content you add or change on your other computer is not sent to this computer.
Typically, a computer stops synchronizing updates when the user has not logged in for a long period of time, approximately three weeks or longer. To stay synchronized between computers, an account needs to be online within reasonable frequency so that the number of updates to be shared does not become too large.
If you suspect that an account on one of your computers has stopped synchronizing updates, you can confirm your suspicion by viewing the status of your account in preferences:
On the File tab, click Info, click Manage Account, and then click Account Preferences.
Click the Account tab.
Look for a Synchronization Alert in the list of your computers.
To resynchronize an account that is no longer synchronizing updates, you must remove the account from the computer, and then re-add the account using a current, saved copy of the account file.
To remove the unsynchronized account, you can simply delete it on the computer on which it resides.