diff --git a/.Rbuildignore b/.Rbuildignore
index aa7059a3b2102a246821ef37d6ddd1d831deb5f0..39771b3df13ec8782f7cfd434821880d1c37ec1a 100644
--- a/.Rbuildignore
+++ b/.Rbuildignore
@@ -9,7 +9,7 @@
 ^inst/doc$
 ^\.gitlab-ci\.yml$
 ## unit tests should be ignored when building the package for CRAN
-^tests$
+# ^tests$
 ^inst/PlotProfiling\.R$
 ^.gitlab$
 # Suggested by http://r-pkgs.had.co.nz/package.html
diff --git a/R/Start.R b/R/Start.R
index 2be297b1cf0df03679544b751ef45ca2b6eabc30..42f72b6ff21519f53409f4269cf345296f78f780 100644
--- a/R/Start.R
+++ b/R/Start.R
@@ -3279,8 +3279,11 @@ Start <- function(..., # dim = indices/selectors,
                       indices_chunk <- c(indices_chunk, rep(item, length(tmp) - length(indices_chunk)))
                     }
                     sub_array_of_indices_by_file <- split(sub_array_of_indices, indices_chunk)
-                    for (item in 2:length(sub_array_of_indices_by_file)) {
-                      sub_array_of_indices_by_file[[item]] <- sub_array_of_indices_by_file[[item]] - cumsum(inner_dim_lengths)[item - 1]
+                    for (item in names((sub_array_of_indices_by_file))) {
+                      # If item is 1, cumsum(inner_dim_lengths)[item - 1] returns numeric(0)
+                      if (as.numeric(item) > 1) {
+                        sub_array_of_indices_by_file[[item]] <- sub_array_of_indices_by_file[[item]] - cumsum(inner_dim_lengths)[as.numeric(item) - 1]
+                      }
                     }
                     transformed_indices <- unlist(sub_array_of_indices_by_file, use.names = FALSE)
                   }