I've used MapInfo for over 20 years and have used FME only a few times. I've been struggling to get the shortestpath finder to run on a large data set. I've read through many of the Q&A here and the documentation and have done the following:

Data sources:

TIGER road network

To/From line segments.

Data prep:

1) I ran the TIGER file through the topologybuilder as was recommended.

2) I used the coordinateextractor to pull the start and end node from each road segment (start = coordinate index 0 and end = coordinate index -1)

3) I used the neighborfinder to run my TO points file (base) to the nearest start/end node (candidate) and used the candidate x/y coordinates for my new TO location. I then did the same thing with my FROM points file.

4) I created a polyline using the new To/From nodes (I did this in MapInfo as I couldn't figure out how to do it within FME)

Up till now, everything worked perfectly. I received no errors and the To/From polyline starts and ends along the network as it should.

5) I ran the shortestpathfinder on my road network and the To/From polyline file. I did not use the snapping since the polyline already falls on the road network nodes. However, I get a string of errors in blue text that says: No shortest path found from (list of coordinates).

The frustrating part is that there are valid routes:

The grey is the road network

The black line is the To/From polyline that gave me the "no route can be find" error.

The green is the highlighted route I created that connects the two nodes. The green line is completely contiguous. 

Does anyone know why it says no shortest path found?