When I reproject my data with FME it appears to be approximately 50ft out of position. What is going wrong

From Fmepedia

Q) When I reproject my data with FME it appears to be approximately 50ft out of position. What is going wrong?

A) There are three likely causes of the problem...

1) You are including a datum conversion in the reprojection and the grid-shift files used were incorrect. Check the log file. It will include information on what datum shift has taken place (if any) and what grid files were used.

2) You are using a coordinate system with the wrong units. This is most likely to occur when confusing the different types of 'foot' unit. See this question for more information on foot measurements in FME, particularly when used with ArcGIS data.

3) You are using a different (possibly incorrect) version of a coordinate system definition. For example, there are several different definitions of the Dutch RD system, National RD/NAP being the most accurate one.