trouble with region.N and multiple sessions

[sixtystrat]

I have a multi-session model with density covariates to model inhomogeneous bear density over a large region.
When I run region.N(model.1) I get an error message:

Error in getcellsize(mask) : mask lacks valid cell size (area or spacing).

I am using 2 masks (1 for each session) and have tried different ways to define the mask and session for region.N but so far none have worked. Anyone have any ideas on what I am doing wrong? Thanks!
Joe

[murray.efford]

Answered on secrgroup