diff --git a/.gitignore b/.gitignore
index ad18f5a8..619c3361 100644
--- a/.gitignore
+++ b/.gitignore
@@ -55,6 +55,7 @@ config.yaml
 
 # virtualenv
 /venv/
+/venv38/
 /py27/
 /py2/
 /django2/
diff --git a/requirements.txt b/requirements.txt
index 8aba5f9a..a237c95a 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -107,7 +107,7 @@ jupyterlab-server==0.3.0
 keyring==18.0.0
 kiwisolver==1.0.1
 kombu==4.5.0
-llvmlite==0.30.0
+llvmlite==0.33.0
 lxml==4.3.2
 Markdown==3.0.1
 MarkupSafe==1.1.1
@@ -126,7 +126,7 @@ nose==1.3.7
 nose-parameterized==0.6.0
 notebook==5.7.6
 numba==0.46.0
-numpy==1.18.3
+numpy==1.18.5
 oauth2==1.9.0.post1
 oauthlib==3.0.1
 openapi-codec==1.3.2
@@ -148,7 +148,7 @@ protobuf==3.11.1
 psycopg2==2.8.1
 ptyprocess==0.6.0
 py==1.8.0
-pyarrow==0.15.0
+pyarrow==0.17.1
 pycairo==1.19.0
 pycparser==2.19
 Pygments==2.3.1
diff --git a/rowers/interactiveplots.py b/rowers/interactiveplots.py
index be7360b5..6ad25d6a 100644
--- a/rowers/interactiveplots.py
+++ b/rowers/interactiveplots.py
@@ -5481,8 +5481,11 @@ def interactive_multiple_compare_chart(ids,xparam,yparam,plottype='line',
         else:
             windowsize = 1
 
-        if windowsize >= 3 and windowsize < len(group['y']):
-            group['y'] = savgol_filter(group['y'],windowsize,3)
+        if windowsize > 3 and windowsize < len(group['y']):
+            try:
+                group['y'] = savgol_filter(group['y'],windowsize,3)
+            except ValueError:
+                pass
 
         ylabel = Label(x=100,y=60+nrworkouts*20-20*cntr,
                        x_units='screen',y_units='screen',
diff --git a/rowers/templates/course_form.html b/rowers/templates/course_form.html
index 5a346104..aa1bb20f 100644
--- a/rowers/templates/course_form.html
+++ b/rowers/templates/course_form.html
@@ -41,6 +41,54 @@
       </form>
     </div>
   </li>
+  <li class="grid_4">
+    <h2>How-to</h2>
+    <p>
+      Courses allow you to mark the start & finish lines of your
+      test pieces and measure the time spent on the course (as opposed
+      to the total duration of a workout). This allows you to row and rank
+      marked courses.
+
+      To create a course, you use <a href="https://www.google.com/earth/">Google Earth</a>
+      to mark the start and finish lines using polygons. The process is identical
+      to creating custom courses for the
+      <a href="http://performancephones.com/crewnerd/">CrewNerd</a>
+      app.
+
+    </p>
+
+    <p>CrewNerd has published a nice video tutorial of the process.
+      <a href="https://youtu.be/whhWFmMJbhM">Click here</a> to see the video. The part
+      we're interested in starts at 2:05.
+    </p>
+
+    <p>
+      In addition to start and finish areas, on rowsandall.com you can add additional
+      polygons to mark areas that you must pass (in that order). This allows for
+      courses with turns around buoys, respecting buoy lines, or respecting traffic
+      patterns on rivers and lakes.
+    </p>
+
+    <p>
+      <ul>
+        <li>Open Google Earth</li>
+        <li>Create a folder "Courses" under "Temporary Places" or under "My Places"</li>
+        <li>Create a folder for each Course under "Courses", and for each course:</li>
+        <li>Create Start polygon</li>
+        <li>Optional: Create First "must row through" polygon</li>
+        <li>Optional: Create subsequent "must row through" polygons</li>
+        <li>Create Finish polygon</li>
+        <li>Save "Courses" as KML file</li>
+        <li>Upload the file to rowsandall.com using the "Add Courses" button</li>
+      </ul>
+    </p>
+
+    <p>You are allowed to have multiple courses in one KML file.
+      Your CrewNerd "courses.kml" file works out of the box</p>
+
+    <p>The site doesn't test for duplicate courses.</p>
+
+  </li>
 </ul>
 
 
diff --git a/rowers/templates/menu_racing.html b/rowers/templates/menu_racing.html
index 67e72c77..9d115550 100644
--- a/rowers/templates/menu_racing.html
+++ b/rowers/templates/menu_racing.html
@@ -112,11 +112,11 @@
           <i class="fas fa-map fa-fw"></i>&nbsp;Map View
         </a>
       </li>
-      {% if course.manager == rower %}
       <li id="course-emailkml">
         <a href="/rowers/courses/{{ course.id }}/downloadkml/">
           <i class="fas fa-globe-americas fa-fw"></i>&nbsp;Download as KML</a>
       </li>
+      {% if course.manager == rower %}
       <li id="course-editview">
         <a href="/rowers/courses/{{ course.id }}/edit/">
           <i class="fas fa-pencil-alt fa-fw"></i>&nbsp;Edit</a>
diff --git a/rowers/views/planviews.py b/rowers/views/planviews.py
index f30b51b9..7db2babe 100644
--- a/rowers/views/planviews.py
+++ b/rowers/views/planviews.py
@@ -81,7 +81,10 @@ def plannedsession_comment_view(request,id=0,userid=0):
                 rowers = {r.user for r in ps.rower.all()}
             commenters = set(list(commenters)+list(rowers))
             for u in commenters:
-                a_messages.info(u,message)
+                try:
+                    a_messages.info(u,message)
+                except ValueError:
+                    pass
                 if u != request.user and u != r.user:
                     ocr = Rower.objects.get(user=u)
                     res = myqueue(queuelow,
diff --git a/rowers/views/racesviews.py b/rowers/views/racesviews.py
index 7d2e2dcf..81d1ab5e 100644
--- a/rowers/views/racesviews.py
+++ b/rowers/views/racesviews.py
@@ -1209,7 +1209,10 @@ def virtualevent_view(request,id=0):
 
     orderby = request.GET.get('order_by')
     if orderby is not None:
-        results = results.order_by(orderby)
+        try:
+            results = results.order_by(orderby)
+        except AttributeError:
+            pass
 
     racelogos = race.logos.all()