for several versions of the App OPlayer, I can not comment on the shared folders on the Mac by smb.
I have an iMac with Captain you and OPlayer in the latest version available on the App Store. I connect from iPad Air2.
Versión iOS: 9.3.2
Versión oplayer: 3.0.1
Versión macos: 10.11.5
You can check this error, thanks