data stringification was not done, when object was not modified, and

passed as it is and that leads to error during fetching the modified
SQL.

Thanks Neel for the point out.

web/pgadmin/static/js/backform.pgadmin.js

@@ -978,7 +978,7 @@
             url: msql_url,
             type: 'GET',
             cache: false,
-            data: self.model.toJSON(true, 0, 'GET'),
+            data: self.model.toJSON(true, 'GET'),
             dataType: "json",
             contentType: "application/json"
           }).done(function(res) {