1 files changed, 5 insertions, 2 deletions
diff --git a/core/DataTable/Row.php b/core/DataTable/Row.php
index bfa1a49667..878c1a61cf 100644
--- a/core/DataTable/Row.php
+++ b/core/DataTable/Row.php
@@ -12,7 +12,6 @@ use Exception;
 use Piwik\Container\StaticContainer;
 use Piwik\DataTable;
 use Piwik\Date;
-use Piwik\Log;
 use Piwik\Metrics;
 use Piwik\Period;
 use Psr\Log\LoggerInterface;
@@ -36,7 +35,8 @@ class Row extends \ArrayObject
      */
     private static $unsummableColumns = array(
         'label' => true,
-        'full_url' => true // column used w/ old Piwik versions,
+        'full_url' => true, // column used w/ old Piwik versions,
+        'ts_archived' => true // date column used in metadata for proportional tooltips
     );
 
     // @see sumRow - implementation detail
@@ -677,6 +677,9 @@ class Row extends \ArrayObject
         if (is_array($columnToSumValue)) {
             $newValue = $thisColumnValue;
             foreach ($columnToSumValue as $arrayIndex => $arrayValue) {
+                if (!is_numeric($arrayIndex) && !$this->isSummableColumn($arrayIndex)) {
+                    continue;
+                }
                 if (!isset($newValue[$arrayIndex])) {
                     $newValue[$arrayIndex] = false;
                 }