Some years have either all or no encounters

[JintaoSHOU]

What's reason for this problem?
Calculating range shift for stratum #1:
2008
1
Error in Data_Fn(Version = Version, FieldConfig = FieldConfig, RhoConfig = RhoConfig, :
Some years have either all or no encounters

[James-Thorson]

What proportion of samples have an encounter? That error occurs when you have a year with either 0% or 100% encounter rate.