diff --git a/api/src/org/labkey/api/reports/report/r/view/HtmlOutput.java b/api/src/org/labkey/api/reports/report/r/view/HtmlOutput.java
index 40a23b1a927..61ba89e4e9f 100644
--- a/api/src/org/labkey/api/reports/report/r/view/HtmlOutput.java
+++ b/api/src/org/labkey/api/reports/report/r/view/HtmlOutput.java
@@ -90,6 +90,9 @@ public HtmlOutputView(ParamReplacement param, String label)
             setLabel(label);
         }
 
+        /**
+         * Loads an HTML file and adds nonces to any embedded <script> tags. Don't call this with files that aren't HTML.
+         */
         @Override
         protected String renderInternalAsString(File file) throws Exception
         {
diff --git a/api/src/org/labkey/api/reports/report/r/view/IpynbOutput.java b/api/src/org/labkey/api/reports/report/r/view/IpynbOutput.java
index 2aba12264b5..6a58911b498 100644
--- a/api/src/org/labkey/api/reports/report/r/view/IpynbOutput.java
+++ b/api/src/org/labkey/api/reports/report/r/view/IpynbOutput.java
@@ -31,6 +31,7 @@
 import org.labkey.api.util.HtmlString;
 import org.labkey.api.util.HtmlStringBuilder;
 import org.labkey.api.util.ImageUtil;
+import org.labkey.api.util.PageFlowUtil;
 import org.labkey.api.view.HttpView;
 import org.labkey.api.view.ViewContext;
 
@@ -92,7 +93,7 @@ public HttpView<?> getView(ViewContext context)
             {
                 String html = view.renderInternalAsString(file);
                 URI baseURI = new URI(AppProps.getInstance().getBaseServerUrl());
-                if (html != null && baseURI != null)
+                if (html != null)
                     thumb = ImageUtil.webThumbnail(context, html, baseURI);
             }
             catch(Exception ignore){}// if we can't get a thumbnail then that is okay; LabKey should use a default
@@ -149,7 +150,8 @@ String stripAnsiColors(String s)
         @Override
         protected String renderInternalAsString(File file) throws Exception
         {
-            String result = StringUtils.trimToEmpty(super.renderInternalAsString(file));
+            // Don't call super.renderInternalAsString(file) since we expect JSON
+            String result = file.exists() ? StringUtils.trimToEmpty(PageFlowUtil.getFileContentsAsString(file)) : "";
             try
             {
                 final JSONObject obj = new JSONObject(result);
diff --git a/api/src/org/labkey/api/util/PageFlowUtil.java b/api/src/org/labkey/api/util/PageFlowUtil.java
index f071aea5a61..9a4538ca586 100644
--- a/api/src/org/labkey/api/util/PageFlowUtil.java
+++ b/api/src/org/labkey/api/util/PageFlowUtil.java
@@ -3166,14 +3166,21 @@ public static String addScriptNonces(String html)
         String ret = "";
         if (doc != null)
         {
-            addScriptNonces(doc);
-            try
+            if (addScriptNonces(doc) > 0)
             {
-                ret = convertNodeToHtml(doc);
+                try
+                {
+                    ret = convertNodeToHtml(doc);
+                }
+                catch (TransformerException | IOException e)
+                {
+                    throw new RuntimeException(e);
+                }
             }
-            catch (TransformerException | IOException e)
+            else
             {
-                throw new RuntimeException(e);
+                // If there are no script tags, just return the passed in HTML
+                ret = html;
             }
         }