diff --git a/CHANGELOG b/CHANGELOG
index 5a0154cc5854851d605781f5d146a1dcd1a299eb..9a5b110fd0620a70b6a309c91481f6262fa34268 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -533,3 +533,9 @@ v2.12
 
 Support running CSO within a virtual environment.
 
+
+v2.13
+-----
+
+Updates for latest python versions.
+Improved error checks.
diff --git a/README.md b/README.md
index a22bda9c240ecece4285e3377818fb8cc0647be5..5f3c04f2330ddbd9670dbd45f4512bc91cae5830 100644
--- a/README.md
+++ b/README.md
@@ -89,6 +89,39 @@ When finished, leave from the virtual environment using:
 
     deactivate
 
+Eventually create the following script that activates the envioronment,
+or creates it if not present yet:
+
+    #
+    # Source this script to setup:
+    #
+    #    .  this_script
+    #
+    
+    # virtual environment exists already?
+    if [ -f .venv/bin/activate ]; then
+
+      # activate:
+      source .venv/bin/activate
+
+    else
+
+      # eventually enable latest python version:
+      #module load python/3.13.1
+
+      # init virtual environment:
+      python3 -m venv --prompt cso .venv
+
+      # activate:
+      source .venv/bin/activate
+
+      # upgrade pip:
+      pip install --upgrade pip
+
+      # install local codes:
+      pip install --editable .
+
+    fi
 
 
 
diff --git a/doc/source/history.rst b/doc/source/history.rst
index d643e088f3df8dc0284432f545bd48a7d2a54651..9294260129788f8d23c55d2c3887f368bd8c697d 100644
--- a/doc/source/history.rst
+++ b/doc/source/history.rst
@@ -118,6 +118,9 @@ A summary of the versions and changes.
   
 * | *v2.12*
   | Support running in Python virtual environment.
+  
+* | *v2.13*
+  | Minor updates to trap errors and support latest Python versions.
 
 
 To be included
@@ -159,7 +162,7 @@ A wishlist of developments.
 How to create a version tag
 ===========================
 
-Example for tag "v2.12".
+Example for tag "v2.13".
 
 1. Update file formatting following conventions.
 
@@ -179,17 +182,17 @@ Example for tag "v2.12".
 
    c. Change the release tag that will also be imported to the documenation in the `pyproject.toml <../../../pyproject.toml>`_ file::
 
-        release = "2.12"
+        release = "2.13"
     
    d. Commit and push these changes::
 
-       git commit -m 'Defined v2.12' .
+       git commit -m 'Defined v2.13' .
        git push
 
 4. Tag and push the code to the git repository::
 
-      git tag -a 'v2.12' -m 'Tagged v2.12'
-      git push origin v2.12
+      git tag -a 'v2.13' -m 'Tagged v2.13'
+      git push origin v2.13
 
 
   
diff --git a/pyproject.toml b/pyproject.toml
index 42d3905d362db84364c18b3055befae78c5fbba5..3ed4cacb9de4683d26701a5b0ce77990f45d53b8 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "setuptools.build_meta"
 
 [project]
 name = "cso"
-version = "2.12"
+version = "2.13"
 authors = [
     { name = "Arjo Segers" },
     { name = "Lewis Blake" },
diff --git a/src/cso/cso_file.py b/src/cso/cso_file.py
index b1f2d854a3f54aad86b9ab85265ac8f06067da6c..aa59f5dd5a1108d68040674eaa50e5a1f3b3e52d 100644
--- a/src/cso/cso_file.py
+++ b/src/cso/cso_file.py
@@ -58,6 +58,9 @@
 # 2025-10, Arjo Segers
 #   Replace ' and ' by ' & ' when selecting records.
 #
+# 2026-01, Arjo Segers
+#   Updated use of Dataset.dims following deprication warning.
+#
 
 ########################################################################
 ###
@@ -1128,7 +1131,7 @@ class CSO_File(object):
         logging.info(indent + "pixel selection ...")
 
         # init selection, by default accept all:
-        selected = numpy.ones((self.ds.dims["pixel"],), "bool")
+        selected = numpy.ones((self.ds.sizes["pixel"],), "bool")
 
         # init history:
         history = []
diff --git a/src/cso/cso_mapping.py b/src/cso/cso_mapping.py
index e23f3df1f6b5af87a04846945293c12644147aaf..fe95bb71d062253aaff32679bdc8b5c9c2ebbdae 100644
--- a/src/cso/cso_mapping.py
+++ b/src/cso/cso_mapping.py
@@ -14,6 +14,9 @@
 # 2023-08, Arjo Segers
 #   Remove rounding errors when locations are very close.
 #
+# 2026-01, Arjo Segers
+#   Changed imports for python packaging.
+#
 
 ########################################################################
 ###
@@ -89,7 +92,7 @@ def LonLatDistance(lon1, lat1, lon2, lat2):
     import numpy
 
     # tools:
-    from cso_constants import EarthRadius
+    from . import cso_constants
 
     # convert:
     delta = lon2 - lon1
@@ -102,7 +105,7 @@ def LonLatDistance(lon1, lat1, lon2, lat2):
     phi = numpy.arccos(x.clip(-1.0, 1.0))  # radians
 
     # in m over the globe:
-    return phi * EarthRadius  # m
+    return phi * cso_constants.EarthRadius  # m
 
 
 # enddef  # LonLatDistance
@@ -176,7 +179,7 @@ def LonLatTrianglesArea(xx, yy):
     import numpy
 
     # tools:
-    from cso_constants import EarthRadius
+    from . import cso_constants
 
     # areas:
     aa = TrianglesArea(numpy.radians(xx), numpy.radians(yy))  # rad2
@@ -186,7 +189,7 @@ def LonLatTrianglesArea(xx, yy):
 
     # areas:
     #       rad2                                m2
-    return aa * numpy.cos(yy_aver) * EarthRadius**2  # m2
+    return aa * numpy.cos(yy_aver) * cso_constants.EarthRadius**2  # m2
 
 
 # enddef LonLatTrianglesArea
diff --git a/src/cso/cso_s5p.py b/src/cso/cso_s5p.py
index 602bdf3a3a5276f58b054ebbe3cdb8fb2891f190..c20275de7bdf90e97dee4964062dcc97786ed63c 100644
--- a/src/cso/cso_s5p.py
+++ b/src/cso/cso_s5p.py
@@ -74,6 +74,10 @@
 #   Trap multiple selections from inquire table as this might indicate
 #   a problem in the table or the selection.
 #
+# 2026-01, Arjo Segers
+#   Updated use of Dataset.dims following deprication warning.
+#   Explicitly defined data type in encoding of time array folowing warning.
+#
 
 
 ########################################################################
@@ -223,9 +227,9 @@ class S5p_File(object):
             self.nscan = ds.sizes["scanline"]
             self.ngpix = ds.sizes["ground_pixel"]
             # number 'atmoshpere' layers:
-            if "layer" in ds.dims.keys():
+            if "layer" in ds.dims:
                 self.nlayer = ds.sizes["layer"]
-            elif "level" in ds.dims.keys():
+            elif "level" in ds.dims:
                 self.nlayer = ds.sizes["level"]
             else:
                 self.nlayer = None
@@ -1408,6 +1412,7 @@ class CSO_S5p_File(cso_file.CSO_File):
                 da.attrs["long_name"] = "time"
                 da.encoding["calendar"] = "standard"
                 da.encoding["units"] = f"seconds since {t0.year}-01-01 00:00:000"
+                da.encoding["dtype"] = "float64"
 
             # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
             # pixel corners: for longitudes, need to ensure that also near dateline
diff --git a/src/cso/cso_superobs.py b/src/cso/cso_superobs.py
index 4e18e4cdbdbd8131b7e16b8d57193ce6cc6e8db3..aec6d443cac3ae870aa1d7f8bc0ed811b95d8c83 100644
--- a/src/cso/cso_superobs.py
+++ b/src/cso/cso_superobs.py
@@ -24,6 +24,12 @@
 # 2025-04, Arjo Segers
 #   Changed imports for python packaging.
 #
+# 2026-01, Arjo Segers
+#   Explicitly defined data type in encoding of time array folowing warning.
+#
+# 2026-01, Alessandro D'ausilio
+#   Trap case that no pixels are selected.
+#
 
 
 ########################################################################
@@ -350,18 +356,20 @@ class CSO_SuperObs(utopya.UtopyaRc):
                 source_file = cso_file.CSO_File(filename=source_filename)
 
                 # filter:
-                selected, history = source_file.SelectPixels(
-                    self.rcf, rcbase, indent=indent + "  "
-                )
+                selected, history = source_file.SelectPixels(self.rcf, rcbase, indent=f"{indent}  ")
                 # info ..
-                logging.info(
-                    indent + "  selected %i / %i pixels .." % (selected.sum(), selected.size)
-                )
+                logging.info(f"{indent}   selected {selected.sum()} / {selected.size} pixels ..")
                 # selected indices:
                 (iipix,) = numpy.where(selected)
                 # number of selected pixels:
                 npix = len(iipix)
 
+                # check ..
+                if npix == 0:
+                    logging.info(f"{indent}     no pixels selected, skip ...")
+                    continue
+                #endif
+
                 # footprint or points?
                 if wtype == "number":
                     # info ...
@@ -738,6 +746,7 @@ class CSO_SuperObs(utopya.UtopyaRc):
                         # ensure correct output:
                         outf.ds[vkey].encoding["units"] = tunits
                         outf.ds[vkey].encoding["calendar"] = "standard"
+                        outf.ds[vkey].encoding["dtype"] = "float64"
                         outf.ds[vkey].encoding["_FillValue"] = None
 
                     else:
diff --git a/src/utopya/utopya_build.py b/src/utopya/utopya_build.py
index e5c02e4b70131f55182823d601e4ee50fee464fe..7be5b31f92c62b6c99f167f94e9f2c5925d4cb21 100644
--- a/src/utopya/utopya_build.py
+++ b/src/utopya/utopya_build.py
@@ -222,10 +222,10 @@ class UtopyaCopy(utopya_rc.UtopyaRc):
     see the initialization of the :py:class:`.UtopyaRc` class for details
     and the necessary configuration of the logging system.
 
-    If the *'new'* flag is present it overwrites the *'\*.copy.new'* flag;
-    set to '*True'* to remove an existing build directory if present.
+    If the ``new`` flag is present it overwrites the ``copy.new`` rcfile setting;
+    set to ``True`` to remove an existing build directory if present.
 
-    The following example shows the required settings for an rcbase *'optm'*.
+    The following example shows the required settings for an rcbase ``optm``.
     The content of the directories::
 
         sources/model/base/src