Since december I have problem with "Dropbox Post-processing engine" on multiple installations. Backup are made properly but postprocess fails. When I try to run file postprocess manually (from backups list) I get an error:
Error expired_access_token: No error description provided. Raw error: Array ( [.tag] => expired_access_token )
If I update authentication steps in configuration then I can postprocess/uplod files to dropbox for one day. Next day the problem occurs again.
When I'm authenticating dropbox, in Popup I have error on the bottom (but it does not affect the generation of keys):
Dropbox Authentication Error invalid_grantDropbox reported that you did not log in correctly or did not grant Akeeba Backup the permission to access your account.