Recently have an example where an attribute for a feature in an Esri Geodatabase where the GDB could be read by FME 2014 SP3 but with FME 2015, 2016 and 2017 the Reader dropped features with no warning message. Opening the GDB in FME 2014 Data Inspector shows some unusual characters in an attribute value.
Tried the File Geodb ArcObjects reader and it writes a useful warning into the log:
2017-08-10 17:30:45| 1.5| 0.0|WARN |Unable to retrieve feature from table/feature class 'IC_POINT'. This feature, and any other feature from 'IC_POINT' that cannot be read, will be skipped. The error number from ArcObjects is: '-2147418113'. The error message from ArcObjects is: {Unexpected operation [IC_POINT]}
Requesting better messages/error detection when reading the GDB with the File Geodb API reader similar to the File Geodb ArcObjects or stop reading the file. It would be then possible to manage rather than losing data.