diff --git a/rowers/dataroutines.py b/rowers/dataroutines.py
index 855d0831..b3e43767 100644
--- a/rowers/dataroutines.py
+++ b/rowers/dataroutines.py
@@ -2126,6 +2126,7 @@ def dataprep(rowdatadf, id=0, bands=True, barchart=True, otwpower=True,
 
         filename = 'media/strokedata_{id}.parquet.gz'.format(id=id)
         df = dd.from_pandas(data, npartitions=1)
+
         if polars:
             pldf = pl.from_pandas(data)
             try:
@@ -2139,6 +2140,10 @@ def dataprep(rowdatadf, id=0, bands=True, barchart=True, otwpower=True,
             except FileNotFoundError:
                 df2 = dd.from_pandas(df, npartitions=1)
                 df2.to_parquet(filename, engine='fastparquet', compression='gzip')
+            except FileExistsError:
+                os.remove(filename)
+                df.to_parquet(filename, engine='fastparquet', compression='GZIP')
+
 
     return data
 
diff --git a/rowers/views/racesviews.py b/rowers/views/racesviews.py
index 483d0d6a..fd1c4259 100644
--- a/rowers/views/racesviews.py
+++ b/rowers/views/racesviews.py
@@ -371,11 +371,14 @@ def course_view(request, id=0):
         coursecompleted=True).order_by("duration", "-distance")
 
     # get own training results
-    ownrecords = CourseTestResult.objects.filter(
-        courseid = course.id,
-        userid = r.id,
-        coursecompleted=True
-    ).order_by("duration", "-distance")
+    if not request.user.is_anonymous:
+        ownrecords = CourseTestResult.objects.filter(
+            courseid = course.id,
+            userid = r.id,
+            coursecompleted=True
+        ).order_by("duration", "-distance")
+    else:
+        ownrecords = []
 
     if request.user.is_authenticated:
         notsharing = Rower.objects.filter(