Update your Dropbox Python Core SDK

Specifically, I mean are you getting anything else from your app (e.g., other output or errors) that leads you to believe that's the case beyond that warning log message though? I believe that warning just indicates that a freed connection wasn't being returned to the pool because the pool is already full, not that any requests are being dropped. It doesn't indicate an issue that necessarily needs to be fixed, but you can increase the max_connections if you want to.