diff --git a/DESCRIPTION b/DESCRIPTION
index b5b99acf..fd0cd0c6 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,6 +1,6 @@
 Package: bmm
 Title: Easy and Accesible Bayesian Measurement Models using 'brms'
-Version: 0.4.5.9000
+Version: 0.4.6.9000
 Authors@R: c(
     person("Vencislav", "Popov", , "vencislav.popov@gmail.com", role = c("aut", "cre", "cph")),
     person("Gidon", "Frischkorn", , "gidon.frischkorn@psychologie.uzh.ch", role = c("aut", "cph")),
diff --git a/NEWS.md b/NEWS.md
index 7bdf858c..76637380 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -9,6 +9,7 @@
 * you can now choose to estimate parameters that are fixed to a constant by default for all models (#145)
 * default priors for all models are now specified via the configure_prior() S3 method (#145)
 * `cmdstanr` will be used as the default backend for `brms` if the user has it installed (#145)
+* various updates to the documentation and data sets
 
 ### Bug fixes
 * fix a bug preventing the sort_data check from being executed (#72)
diff --git a/R/bmm_model_IMM.R b/R/bmm_model_IMM.R
index 9a1215ec..8d8acec1 100644
--- a/R/bmm_model_IMM.R
+++ b/R/bmm_model_IMM.R
@@ -293,6 +293,9 @@ check_data.IMMspatial <- function(model, data, formula) {
          "The number of columns for non-target distances in the argument \\
          'nt_distances' should equal max(setsize)-1})")
 
+  # replace nt_distances
+  data[,nt_distances][is.na(data[,nt_distances])] <- 999
+
   stopif(any(data[,nt_distances] < 0),
          "All non-target distances to the target need to be postive.")
 
diff --git a/data/OberauerLin_2017.rda b/data/OberauerLin_2017.rda
index 8f74fe15..09ed3ba4 100644
Binary files a/data/OberauerLin_2017.rda and b/data/OberauerLin_2017.rda differ
diff --git a/man/configure_model.Rd b/man/configure_model.Rd
index 869bd9d5..3015592e 100644
--- a/man/configure_model.Rd
+++ b/man/configure_model.Rd
@@ -79,7 +79,8 @@ configure_model.mixture3p <- function(model, data, formula) {
   for (i in 1:(max_setsize - 1)) {
     formula <- formula +
       glue_nlf("{kappa_nts[i]} ~ kappa") +
-      glue_nlf("{theta_nts[i]} ~ {lure_idx[i]} * (thetant + log(inv_ss)) + (1 - {lure_idx[i]}) * (-100)") +
+      glue_nlf("{theta_nts[i]} ~ {lure_idx[i]} * (thetant + log(inv_ss)) + ",
+               "(1 - {lure_idx[i]}) * (-100)") +
       glue_nlf("{mu_nts[i]} ~ {nt_features[i]}")
   }
 
diff --git a/tests/testthat/test-bmm_model_IMM.R b/tests/testthat/test-bmm_model_IMM.R
index 6fcb43d0..34578bf3 100644
--- a/tests/testthat/test-bmm_model_IMM.R
+++ b/tests/testthat/test-bmm_model_IMM.R
@@ -147,13 +147,13 @@ test_that('IMM models run when setsize is a predictor and intercept is supressed
   formula <- bmf(
     kappa ~ 1,
     c ~ 1,
-    s ~ 0+set_size
+    s ~ 0 + set_size
   )
   model <- IMMbsc(resp_err = 'dev_rad',
                   nt_features = paste0("col_nt",1:7),
                   nt_distances = paste0("dist_nt",1:7),
                   setsize = "set_size")
-  expect_silent(fit_model(formula, dat, model, backend = 'mock', mock=1, rename = F))
+  expect_silent(fit_model(formula, dat, model, backend = 'mock', mock = 1, rename = F))
 
 
   formula <- bmf(