diff --git a/libraries/classes/Error.php b/libraries/classes/Error.php
index 7c318a24b4..23416e4bfa 100644
--- a/libraries/classes/Error.php
+++ b/libraries/classes/Error.php
@@ -104,10 +104,15 @@ class Error extends Message
         $this->setFile($errfile);
         $this->setLine($errline);
 
-        $backtrace = debug_backtrace();
-        // remove last three calls:
-        // debug_backtrace(), handleError() and addError()
-        $backtrace = array_slice($backtrace, 3);
+        // This function can be disabled in php.ini
+        if (function_exists('debug_backtrace')) {
+            $backtrace = @debug_backtrace();
+            // remove last three calls:
+            // debug_backtrace(), handleError() and addError()
+            $backtrace = array_slice($backtrace, 3);
+        } else {
+            $backtrace = array();
+        }
 
         $this->setBacktrace($backtrace);
     }
diff --git a/libraries/classes/Plugins/Export/ExportSql.php b/libraries/classes/Plugins/Export/ExportSql.php
index 3c74d1b2fb..bde8d4eaf5 100644
--- a/libraries/classes/Plugins/Export/ExportSql.php
+++ b/libraries/classes/Plugins/Export/ExportSql.php
@@ -1388,7 +1388,7 @@ class ExportSql extends ExportPlugin
 
         // need to use PhpMyAdmin\DatabaseInterface::QUERY_STORE
         // with $GLOBALS['dbi']->numRows() in mysqli
-        $result = $GLOBALS['dbi']->query(
+        $result = $GLOBALS['dbi']->tryQuery(
             'SHOW TABLE STATUS FROM ' . Util::backquote($db)
             . ' WHERE Name = \'' . $GLOBALS['dbi']->escapeString($table) . '\'',
             null,