You tried to share or unshare a folder that contains a very large number of files.
How to fix it:
If you’re trying to share a folder, follow these steps:
Sign in to dropbox.com.
Locate the folder with too many files and rename it.
Click New shared folder.
Choose I’d like to create and share a new folder.
Add a name for your folder, then add the email addresses of the people you want to share with in the To: box.
In the Dropbox desktop app, open the old folder you wanted to share.
Copy all files in this folder.
Open your new shared folder.
Paste files from the old folder into the new shared folder. Now, these files will sync with shared folder members.
This error only affects the creation of a shared folder and won't affect future invitations to the folder.
If you’re trying to unshare a folder, follow these steps:
On your computer, move the contents of the shared folder into a non-shared folder.
Let Dropbox sync this move.
Unshare the now empty shared folder.
Move the contents back into the now unshared folder, or delete the now unshared folder and use the new folder.
Error: "You sent too many invitations."
You sent a lot of invitations in a short period of time. To prevent abuse, there is a limit on how many shared folder invitations you can send in one day.
How to fix it:
If you hit the limit, wait 24 hours before trying to send another invitation.
Message: "Folder updates in progress- please try again later."
Occasionally, you may see a "Folder updates in progress" message on dropbox.com. This message can appear if you try to:
Share a folder
Move a folder
Upload a file to the folder
Edit a file in the folder
Edit the folder itself
Change folder access levels
This error message means that a "lock" is in place—the folder is locked, and blocking you from performing some action. A folder becomes locked when you or another folder member perform several actions at the same time. This includes:
Editing a folder or its files from one device while it's still syncing changes you made on another device
Sharing a folder while it's syncing changes made by another member
Updating a folder while it's syncing changes made by another member, including:
Edits to the same file(s) in the folder
Changes to the folder itself, like changing its name
Changes to the membership of the folder (shared with new members, or current members are being removed)
Changes to the folder permissions (whether members can view or edit its files)
How to fix it:
If you encounter an "…updates in progress" error, the easiest fix is to simply wait and try again later. This resolves most syncing locks. If you've waited but still encounter the error, read on.
In most cases the duration of the lock is very short. However, the time it takes for the lock to go away depends on several factors, including:
The number of files in the folder
The number of members in the folder
The number of sub-folders inside this main folder
The folder is locked because of changes made by another member
If this is the case, contact the other member(s) of the folder and ask that they stop making changes in the folder. You can then try again. If you still encounter the error message, you may need to ask the other member(s) to pause syncing.