diff --git a/R/NcDataReader.R b/R/NcDataReader.R
index c5ec75eb4e3fb26a4dca44658c4a5d90bb998a89..11bc7d4043275e56e44b7f081252083d8de24c55 100644
--- a/R/NcDataReader.R
+++ b/R/NcDataReader.R
@@ -39,7 +39,8 @@ NcDataReader <- function(file_path = NULL, file_object = NULL,
     position_of_var <- length(inner_indices)
   } else {
     stop("A 'var'/'variable' file dimension or inner dimension must be ",
-         "requested for NcDataReader() to read NetCDF files.")
+         "requested for NcDataReader() to read NetCDF files with more than ",
+         "one variable.")
   }
 
   inner_indices[[position_of_var]] <- sapply(inner_indices[[position_of_var]],
@@ -114,15 +115,17 @@ NcDataReader <- function(file_path = NULL, file_object = NULL,
     result <- easyNCDF::NcToArray(file_to_read, inner_indices, drop_var_dim = drop_var_dim,
                                   expect_all_indices = TRUE, allow_out_of_range = TRUE)
   }
-  names(dim(result)) <- sapply(names(dim(result)),
-    function(x) {
-      which_entry <- which(sapply(synonims, function(y) x %in% y))
-      if (length(which_entry) > 0) {
-        names(synonims)[which_entry]
-      } else {
-        x
-      }
-    })
+  if (!is.null(dim(result))) {
+    names(dim(result)) <- sapply(names(dim(result)),
+      function(x) {
+        which_entry <- which(sapply(synonims, function(y) x %in% y))
+        if (length(which_entry) > 0) {
+          names(synonims)[which_entry]
+        } else {
+          x
+        }
+      })
+  }
   names(attr(result, 'variables')) <- sapply(names(attr(result, 'variables')),
     function(x) {
       which_entry <- which(sapply(synonims, function(y) x %in% y))
diff --git a/R/Start.R b/R/Start.R
index b1889f0cdd35f4cee22e84eb74aa96344b33e8c4..2854453fc65ee7b90c39a639dda28d66a1a6b9f3 100644
--- a/R/Start.R
+++ b/R/Start.R
@@ -209,7 +209,7 @@ Start <- function(..., # dim = indices/selectors,
       .warning(paste0("A reorder for the selectors of '", pattern_dim, 
                       "' has been specified, but it is a pattern dimension and the reorder will be ignored."))
     }
-    if (any(sapply(dat, is.list))) {
+    if (is.list(dat) || any(sapply(dat, is.list))) {
       if (is.null(found_pattern_dim)) {
         found_pattern_dim <- pattern_dim
       } else {
@@ -218,13 +218,15 @@ Start <- function(..., # dim = indices/selectors,
     }
   }
   if (is.null(found_pattern_dim)) {
-    .warning(paste0("Taking the first pattern dim, '", pattern_dims[1], "', as dimension with pattern specifications (to be fetched in configuration file)."))
+    .warning(paste0("Could not find any pattern dim with explicit data set descriptions (in the form of list of lists). Taking the first pattern dim, '", pattern_dims[1], "', as dimension with pattern specifications."))
     found_pattern_dim <- pattern_dims[1]
   }
 
   # Check metadata_dims
   if (!is.null(metadata_dims)) {
-    if (!is.character(metadata_dims) || (length(metadata_dims) < 1)) {
+    if (is.na(metadata_dims)) {
+      metadata_dims <- NULL
+    } else if (!is.character(metadata_dims) || (length(metadata_dims) < 1)) {
       stop("Parameter 'metadata' dims must be a vector of at least one character string.")
     }
   } else {
@@ -240,6 +242,10 @@ Start <- function(..., # dim = indices/selectors,
   dat_names <- c()
   if (!is.list(dat)) {
     dat <- as.list(dat)
+  } else {
+    if (!any(sapply(dat, is.list))) {
+      dat <- list(dat)
+    }
   }
   for (i in 1:length(dat)) {
     if (is.character(dat[[i]]) && length(dat[[i]]) == 1 && nchar(dat[[i]]) > 0) {
@@ -283,6 +289,10 @@ Start <- function(..., # dim = indices/selectors,
   if ((length(dat_to_fetch) > 0) && (length(dat_to_fetch) < length(dat))) {
     .warning("'path' has been provided for some datasets. Any information in the configuration file related to these will be ignored.")
   }
+  if (length(dat_to_fetch) > 0) {
+    stop("Specified only the name for some data sets, but not the path ",
+         "pattern. This option has not been yet implemented.")
+  }
 
   # Reorder inner_dims_across_files (to make the keys be the file dimensions,
   # and the values to be the inner dimensions that go across it).
@@ -498,7 +508,10 @@ debug <- TRUE
     dat_selectors <- dim_params
     dat_selectors[[found_pattern_dim]] <- dat_selectors[[found_pattern_dim]][i]
     dim_vars <- paste0('$', dim_names, '$')
-    file_dims <- dim_names[which(sapply(dim_vars, grepl, dat[[i]][['path']], fixed = TRUE))]
+    file_dims <- which(sapply(dim_vars, grepl, dat[[i]][['path']], fixed = TRUE))
+    if (length(file_dims) > 0) {
+      file_dims <- dim_names[file_dims]
+    }
     file_dims <- unique(c(pattern_dims, file_dims))
     found_file_dims[[i]] <- file_dims
     expected_inner_dims[[i]] <- dim_names[which(!(dim_names %in% file_dims))]
@@ -554,8 +567,10 @@ debug <- TRUE
       j <- j + 1
     }
     # (Check the metadata_dims).
-    if (any(!(metadata_dims %in% file_dims))) {
-      stop("All dimensions in 'metadata_dims' must be file dimensions.")
+    if (!is.null(metadata_dims)) {
+      if (any(!(metadata_dims %in% file_dims))) {
+        stop("All dimensions in 'metadata_dims' must be file dimensions.")
+      }
     }
     # (Check the *_var parameters).
     if (any(!(unlist(var_params) %in% names(return_vars)))) {
@@ -2247,11 +2262,13 @@ print("-> PROCEEDING TO CROP VARIABLES")
   }
   # Creating a shared tmp folder to store metadata from each chunk
   array_of_metadata_flags <- array(FALSE, dim = dim(array_of_files_to_load))
-  metadata_indices_to_load <- as.list(rep(1, length(dim(array_of_files_to_load))))
-  names(metadata_indices_to_load) <- names(dim(array_of_files_to_load))
-  metadata_indices_to_load[metadata_dims] <- as.list(rep(TRUE, length(metadata_dims)))
-  array_of_metadata_flags <- do.call('[<-', c(list(array_of_metadata_flags),  metadata_indices_to_load,
-                                              list(value = rep(TRUE, prod(dim(array_of_files_to_load)[metadata_dims])))))
+  if (!is.null(metadata_dims)) {
+    metadata_indices_to_load <- as.list(rep(1, length(dim(array_of_files_to_load))))
+    names(metadata_indices_to_load) <- names(dim(array_of_files_to_load))
+    metadata_indices_to_load[metadata_dims] <- as.list(rep(TRUE, length(metadata_dims)))
+    array_of_metadata_flags <- do.call('[<-', c(list(array_of_metadata_flags),  metadata_indices_to_load,
+                                                list(value = rep(TRUE, prod(dim(array_of_files_to_load)[metadata_dims])))))
+  }
   metadata_file_counter <- 0
   metadata_folder <- tempfile('metadata')
   dir.create(metadata_folder)
@@ -2500,13 +2517,17 @@ print("-> WORK PIECES BUILT")
   gc()
 
   # Load metadata and remove the metadata folder
-  loaded_metadata_files <- list.files(metadata_folder)
-  loaded_metadata <- lapply(paste0(metadata_folder, '/', loaded_metadata_files), readRDS)
-  unlink(metadata_folder, recursive = TRUE)
-  return_metadata <- vector('list', length = prod(dim(array_of_metadata_flags)[metadata_dims]))
-  return_metadata[as.numeric(loaded_metadata_files)] <- loaded_metadata
-  dim(return_metadata) <- dim(array_of_metadata_flags[metadata_dims])
-  attr(data_array, 'variables') <- return_metadata
+  if (!is.null(metadata_dims)) {
+    loaded_metadata_files <- list.files(metadata_folder)
+    loaded_metadata <- lapply(paste0(metadata_folder, '/', loaded_metadata_files), readRDS)
+    unlink(metadata_folder, recursive = TRUE)
+    return_metadata <- vector('list', length = prod(dim(array_of_metadata_flags)[metadata_dims]))
+    return_metadata[as.numeric(loaded_metadata_files)] <- loaded_metadata
+    dim(return_metadata) <- dim(array_of_metadata_flags[metadata_dims])
+    attr(data_array, 'variables') <- return_metadata
+    # TODO: Try to infer data type from loaded_metadata
+    # as.integer(data_array) 
+  }
 
   failed_pieces <- work_pieces[which(unlist(found_files))]
   for (failed_piece in failed_pieces) {
diff --git a/R/Subset.R b/R/Subset.R
index a084a1c2ff3526c460bdcc87e8741cfa355d0386..c82b0c67f6804ab2a3ce9127ede530a6fbe4cbb2 100644
--- a/R/Subset.R
+++ b/R/Subset.R
@@ -78,11 +78,15 @@ Subset <- function(x, along, indices, drop = FALSE) {
     metadata[['dim']] <- metadata[['dim']][-dims_to_drop]
     if (is.character(dim_names)) {
       names(metadata[['dim']]) <- dim_names[-dims_to_drop]
-      metadata[['dimensions']] <- dim_names[-dims_to_drop]
+      if ('dimensions' %in% names(attributes(x))) {
+        metadata[['dimensions']] <- dim_names[-dims_to_drop]
+      }
     }
   } else if (is.character(dim_names)) {
     names(metadata[['dim']]) <- dim_names
-    metadata[['dimensions']] <- dim_names
+    if ('dimensions' %in% names(attributes(x))) {
+      metadata[['dimensions']] <- dim_names
+    }
   }
   attributes(subset) <- metadata
   subset
diff --git a/R/Utils.R b/R/Utils.R
index 24437ace9601c10a519e0cde6a4529d509a634b1..7464a9de2f02506ab7d8651d3e4ee92e5b2d6f8a 100644
--- a/R/Utils.R
+++ b/R/Utils.R
@@ -440,33 +440,41 @@ indices <- function(x) {
 #    'a'   'b'   'c'   'e'   'd'   'f'   'g'
 #     2     4     3     7     5     9     11
 .MergeArrays <- function(array1, array2, along) {
-  if (!(identical(names(dim(array1)), names(dim(array2))) &&
-      identical(dim(array1)[-which(names(dim(array1)) == along)],
-                dim(array2)[-which(names(dim(array2)) == along)]))) {
-    new_dims <- .MergeArrayDims(dim(array1), dim(array2))
-    dim(array1) <- new_dims[[1]]
-    dim(array2) <- new_dims[[2]]
-    for (j in 1:length(dim(array1))) {
-      if (names(dim(array1))[j] != along) {
-        if (dim(array1)[j] != dim(array2)[j]) {
-          if (which.max(c(dim(array1)[j], dim(array2)[j])) == 1) {
-            na_array_dims <- dim(array2)
-            na_array_dims[j] <- dim(array1)[j] - dim(array2)[j]
-            na_array <- array(dim = na_array_dims)
-            array2 <- abind(array2, na_array, along = j)
-            names(dim(array2)) <- names(na_array_dims)
-          } else {
-            na_array_dims <- dim(array1)
-            na_array_dims[j] <- dim(array2)[j] - dim(array1)[j]
-            na_array <- array(dim = na_array_dims)
-            array1 <- abind(array1, na_array, along = j)
-            names(dim(array1)) <- names(na_array_dims)
+  if (!(is.null(array1) || is.null(array2))) {
+    if (!(identical(names(dim(array1)), names(dim(array2))) &&
+        identical(dim(array1)[-which(names(dim(array1)) == along)],
+                  dim(array2)[-which(names(dim(array2)) == along)]))) {
+      new_dims <- .MergeArrayDims(dim(array1), dim(array2))
+      dim(array1) <- new_dims[[1]]
+      dim(array2) <- new_dims[[2]]
+      for (j in 1:length(dim(array1))) {
+        if (names(dim(array1))[j] != along) {
+          if (dim(array1)[j] != dim(array2)[j]) {
+            if (which.max(c(dim(array1)[j], dim(array2)[j])) == 1) {
+              na_array_dims <- dim(array2)
+              na_array_dims[j] <- dim(array1)[j] - dim(array2)[j]
+              na_array <- array(dim = na_array_dims)
+              array2 <- abind(array2, na_array, along = j)
+              names(dim(array2)) <- names(na_array_dims)
+            } else {
+              na_array_dims <- dim(array1)
+              na_array_dims[j] <- dim(array2)[j] - dim(array1)[j]
+              na_array <- array(dim = na_array_dims)
+              array1 <- abind(array1, na_array, along = j)
+              names(dim(array1)) <- names(na_array_dims)
+            }
           }
         }
       }
     }
+    if (!(along %in% names(dim(array2)))) {
+      stop("The dimension specified in 'along' is not present in the ",
+           "provided arrays.")
+    }
+    array1 <- abind(array1, array2, along = which(names(dim(array1)) == along))
+    names(dim(array1)) <- names(dim(array2))
+  } else if (is.null(array1)) {
+    array1 <- array2
   }
-  array1 <- abind(array1, array2, along = which(names(dim(array1)) == along))
-  names(dim(array1)) <- names(dim(array2))
   array1
 }