I am having troubles syncing attachments from an offline map using collector. Has anyone had this problem?
Do you use hosted services or feature services on ArcGIS for Server?
What error message are you getting? Are you using an iOS or Android device?
We have found that using a Sony Android Tablet we cannot collect more that 5 features with attachments without syncing. see https://community.esri.com/thread/90833
the size restrictions on Android is now matching iOS so the 10.2.3 Android size limitation issue was fixed in 10.2.4. What error are you seeing when syncing back? Have you tried syncing on different networks to see if it could be a network issue?
thanks Russell. I will check that the app has been updated on the device and do some testing.