diff --git a/README.rst b/README.rst
index 4af7898195385c7c3c1f6f7517451e6737404491..f352ecfcb8fab295c2fba3bf4a91e174a15a5812 100644
--- a/README.rst
+++ b/README.rst
@@ -141,7 +141,7 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 Change history
 --------------
 
-Version 2.26a (05/01/2017)
+Version 2.26a (05/09/2017)
 
 - Added command line options --no-collect-includes and
   --no-redefine-groups.  These options selectively turn off tasks
@@ -153,7 +153,12 @@ Version 2.26a (05/01/2017)
   Florian Wilmshoever for reporting and working with me on this.
 - Moved README to README.rst so that hopefully Bitbucket will
   render it as reStructuredText (with Docutils).  Also, fixed a
-  number of reST/Docutils errors in README.rst
+  number of reST/Docutils errors in README.rst.
+- Another fix for unicode encoding in process_includes.py.
+- A bug was uncovered when the "-o" command line option is omitted
+  and the Python version is 3.  Added a check that forces the use of
+  the "-o" option unless the one-per option is included.  Thanks to
+  Oskari Petas for reporting this.
 
 Version 2.25a (03/21/2017)
 
diff --git a/generateDS.html b/generateDS.html
index 535d850f436912a4613464976f78c03f83ffb19c..cd00184dbc45e790e32604e215a32360b28910d0 100644
--- a/generateDS.html
+++ b/generateDS.html
@@ -229,7 +229,7 @@ They are used by updateversion.py. -->
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
-<tr class="field"><th class="field-name">date:</th><td class="field-body">May 02, 2017</td>
+<tr class="field"><th class="field-name">date:</th><td class="field-body">May 09, 2017</td>
 </tr>
 </tbody>
 </table>
@@ -3235,7 +3235,7 @@ following among others:</p>
 <div class="footer">
 <hr class="footer" />
 <a class="reference external" href="generateDS.txt">View document source</a>.
-Generated on: 2017-05-02 19:14 UTC.
+Generated on: 2017-05-09 21:57 UTC.
 Generated by <a class="reference external" href="http://docutils.sourceforge.net/">Docutils</a> from <a class="reference external" href="http://docutils.sourceforge.net/rst.html">reStructuredText</a> source.
 
 </div>
diff --git a/generateDS.py b/generateDS.py
index 693cef95242fa646ea4a5c0eb8dd383c763efa0d..54f26f7f7ae9fd577ec71ebbdfa3e7fefff058e5 100755
--- a/generateDS.py
+++ b/generateDS.py
@@ -6546,8 +6546,7 @@ def generate(outfileName, subclassFilename, behaviorFilename,
     MappingTypes.clear()
     AlreadyGenerated = set()
     outfile = None
-    if outfileName:
-        outfile = makeFile(outfileName)
+    outfile = makeFile(outfileName)
     if not outfile:
         outfile = os.tmpfile()
     wrt = outfile.write
@@ -6574,6 +6573,8 @@ def generate(outfileName, subclassFilename, behaviorFilename,
         if not isNewState():
             sys.stderr.write('\n*** maxLoops exceeded.  Something is '
                              'wrong with --one-file-per-xsd.\n\n')
+            sys.stderr.write('*** Failed to process the following element '
+                'definitions:\n    %s\n' % (PostponedExtensions))
             break
         element = PostponedExtensions.pop()
         parentName, parent = getParentName(element)
@@ -7197,6 +7198,8 @@ def main():
     TEMPLATE_MAIN = fixSilence(TEMPLATE_MAIN, silent)
     TEMPLATE_SUBCLASS_FOOTER = fixSilence(TEMPLATE_SUBCLASS_FOOTER, silent)
     load_config()
+    if outFilename is None and SingleFileOutput:
+        sys.exit('\nMissing required option "-o" (output module name)\n')
     parseAndGenerate(
         outFilename,
         subclassFilename,
diff --git a/generateds_gui_notes.html b/generateds_gui_notes.html
index 58e6b4e20855bf8cfd05969f8cf5911bc6202883..a34f76b1c8a5e1d0240aedf76fb1a1052bb7a1bf 100644
--- a/generateds_gui_notes.html
+++ b/generateds_gui_notes.html
@@ -229,7 +229,7 @@ They are used by updateversion.py. -->
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
-<tr class="field"><th class="field-name">date:</th><td class="field-body">April 28, 2017</td>
+<tr class="field"><th class="field-name">date:</th><td class="field-body">May 09, 2017</td>
 </tr>
 </tbody>
 </table>
@@ -401,7 +401,7 @@ $ mv generateds_gui.mo locale/ru/LC_MESSAGES/
 <div class="footer">
 <hr class="footer" />
 <a class="reference external" href="generateds_gui_notes.txt">View document source</a>.
-Generated on: 2017-04-28 21:54 UTC.
+Generated on: 2017-05-09 21:57 UTC.
 Generated by <a class="reference external" href="http://docutils.sourceforge.net/">Docutils</a> from <a class="reference external" href="http://docutils.sourceforge.net/rst.html">reStructuredText</a> source.
 
 </div>
diff --git a/librarytemplate_howto.html b/librarytemplate_howto.html
index b5fa21220f076c9398bdb783924c8bd6a05f0618..5d3738abc667233576c78d8b99a04883228aafc4 100644
--- a/librarytemplate_howto.html
+++ b/librarytemplate_howto.html
@@ -226,7 +226,7 @@ dkuhlman (at) davekuhlman (dot) org
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
-<tr class="field"><th class="field-name">date:</th><td class="field-body">April 28, 2017</td>
+<tr class="field"><th class="field-name">date:</th><td class="field-body">May 09, 2017</td>
 </tr>
 </tbody>
 </table>
@@ -380,7 +380,7 @@ this command for your needs.  For example, you may need to use
 <div class="footer">
 <hr class="footer" />
 <a class="reference external" href="librarytemplate_howto.txt">View document source</a>.
-Generated on: 2017-04-28 21:54 UTC.
+Generated on: 2017-05-09 21:57 UTC.
 Generated by <a class="reference external" href="http://docutils.sourceforge.net/">Docutils</a> from <a class="reference external" href="http://docutils.sourceforge.net/rst.html">reStructuredText</a> source.
 
 </div>
diff --git a/process_includes.py b/process_includes.py
index 17539a0abc2c4f21b9cc6ed877281d1bad9f945e..e030a21d45a8dff9bb41e29d3e8869c17d381c5d 100755
--- a/process_includes.py
+++ b/process_includes.py
@@ -213,7 +213,11 @@ def resolve_ref(node, params, options):
             else:
                 if os.path.exists(locn):
                     infile = open(locn)
-                    content = infile.read().encode()
+                    unencoded_content = infile.read()
+                    if sys.version_info.major == 2:
+                        content = unencoded_content
+                    else:
+                        content = unencoded_content.encode()
                     infile.close()
                     params.parent_url = locn
                     params.base_url = os.path.split(locn)[0]
diff --git a/tutorial/generateds_tutorial.html b/tutorial/generateds_tutorial.html
index 1aa034103fc9040d0c8ea6b86fcbad1b5dd3f6d5..4ee1307a50fe4dadabb3be865ec6694e242ffcd4 100644
--- a/tutorial/generateds_tutorial.html
+++ b/tutorial/generateds_tutorial.html
@@ -228,7 +228,7 @@ They are used by updateversion.py. -->
 <col class="field-name" />
 <col class="field-body" />
 <tbody valign="top">
-<tr class="field"><th class="field-name">date:</th><td class="field-body">April 28, 2017</td>
+<tr class="field"><th class="field-name">date:</th><td class="field-body">May 09, 2017</td>
 </tr>
 </tbody>
 </table>
@@ -1210,7 +1210,7 @@ named <tt class="docutils literal">garden_api.py</tt>, you can create an instanc
 <div class="footer">
 <hr class="footer" />
 <a class="reference external" href="generateds_tutorial.txt">View document source</a>.
-Generated on: 2017-04-28 21:54 UTC.
+Generated on: 2017-05-09 21:57 UTC.
 Generated by <a class="reference external" href="http://docutils.sourceforge.net/">Docutils</a> from <a class="reference external" href="http://docutils.sourceforge.net/rst.html">reStructuredText</a> source.
 
 </div>
diff --git a/tutorial/generateds_tutorial.zip b/tutorial/generateds_tutorial.zip
index 5ac7b6ccf4e3a8b441ef4d6e00a77c913ecfe37a..490a139bad4144c6118c1b4a99694371778130b9 100644
Binary files a/tutorial/generateds_tutorial.zip and b/tutorial/generateds_tutorial.zip differ