diff --git a/src/datatypes/Json.php b/src/datatypes/Json.php
index 4e5aa9e2..8ac78b04 100644
--- a/src/datatypes/Json.php
+++ b/src/datatypes/Json.php
@@ -62,6 +62,19 @@ public function getFeed($url, $settings, $usePrimaryElement = true)
             return ['success' => false, 'error' => $error];
         }
 
+        // if we have empty keys in the array - throw an error, that's not allowed
+        $containsEmptyKeys = false;
+        array_walk_recursive($array, function($value, $key) use (&$containsEmptyKeys) {
+            if (trim($key) === '') {
+                $containsEmptyKeys = true;
+            }
+        });
+        if ($containsEmptyKeys) {
+            $error = 'Invalid Data: data contains empty headings (keys)';
+            Plugin::error($error);
+            return ['success' => false, 'error' => $error];
+        }
+
         // If using pagination, set it up here - we need to do this before messing around with the primary element
         $this->setupPaginationUrl($array, $settings);
 
diff --git a/src/templates/feeds/_map.html b/src/templates/feeds/_map.html
index dbdc27a4..bb3f5f1f 100644
--- a/src/templates/feeds/_map.html
+++ b/src/templates/feeds/_map.html
@@ -62,6 +62,12 @@
             <h2>{{ 'Unable to proceed to field mapping'|t('feed-me') }}</h2>
             <p>{{ 'Feed Me is unable to find, or parse your provided data. This usually means your URL cannot be reached from your Craft site, or your {feedType} is invalid. Check the logs, and double-check your settings.'|t('feed-me', { feedType: feed.feedType|upper }) }}</p>
 
+            {% if feedMappingData.error is not empty %}
+                <div class="fullpage-error-message">
+                    <code>{{ feedMappingData.error }}</code>
+                </div>
+            {% endif %}
+
             <div class="buttons">
                 <a href="{{ url('feed-me/feeds/' ~ feed.id) }}" class="btn submit">&larr; {{ 'Back to feed'|t('feed-me') }}</a>
                 <a href="{{ url('feed-me/logs') }}" class="btn submit">{{ 'Go to logs'|t('feed-me') }}</a>