Issues with Token Expiry and Auto-Refreshing in SwiftyDropbox for multiusers

odoerlek Здравко is correct; in order for the SDK to perform the refresh for you automatically, the client needs to have the necessary credentials, such as the refresh token. In your code you are creating DropboxClient objects with only the access token but not the refresh token, so it can't refresh for you automatically.

I recommend using the client management functionality built in to the SDK whenever possible. For instance, you can use use DropboxClientsManager.reauthorizeClient to switch between stored clients (including their refresh tokens), so that you can then use the DropboxClientsManager.authorizedClient provided by the client. Calling reauthorizeClient will update which client is returned by DropboxClientsManager.authorizedClient.

If you do want to create and manage the clients yourself though, you'll need to make sure you supply the refresh tokens as well, in which case it will catch and handle expired access token errors for you automatically.