NA is not a valid rownumber

[jstabach]

I'm trying to duplicate the tutorial to animate animal locations with a dynamic background (e.g., MODIS NDVI). When I try to do so with my own data, I receive the following error when executing the frames_spatial function:

frames <- frames_spatial(m, r_list = ndvi, r_times = ndvi_times,

•                      fade_raster = TRUE, r_type = "gradient",
  

•                      trace_show = T, trace_colour = "white")
  

Checking temporal alignment...
Processing movement data...
Approximated animation duration: ≈ 21.12s at 25 fps for 528 frames
Assigning raster maps to frames...
Error in .local(x, ...) : NA is not a valid rownumber

I am able to create the two ancillary graphics detailed in the code (frames_graph(graph_type = "flow") and frames_graph(graph_type = "hist")) without issue. Attaching a .Rda file with sample data and a script to re-create the error I am receiving. Thanks for any thoughts/suggestions on what I'm missing.
Movement_Animation_Example.zip