Cannot Reproject NAD27 - NAD83 on FME Flow

Consideration

You have a workspace that does a coordinate system transformation or reprojection with a datum transformation between NAD27 and NAD83. This workspace succeeds in FME Workbench on FME Form (formerly FME Desktop) but fails when run on FME Flow (formerly FME Server). The error in the log file may look something like this:

 Reproject: Could not reproject the geometry of the preceding feature: Reprojector: Could not create reprojection engine

Why This Happens

This problem occurs because FME needs to know whether the data is in Canada or the US. The grid shift files used in Canada for the NTv2 transformation and in the US for the NADCON transformation have overlapping bounding boxes, so without this setting, FME may choose the wrong one. If the setting is not configured, FME will fail rather than risk using the wrong transformation.

In FME Workbench, you are prompted to set this setting during installation. You can access it from the menu Tools > FME Options > Coordinate Systems. FME Flow has no default for this setting, so the transformation cannot be done until the setting is made.

How to Resolve It

On your FME Flow machine, you must set FME to do either NAD84 <-> NAD27 transformations in Canada or the USA.

To configure this, follow the FME Flow Admin Guide's instructions: Configuring Implicit NAD27 to NAD83 Datum Shifts.

Then restart FME Flow and rerun the workspace to see if it completes successfully.