if param.schema doesn't exist, then the line will fail

use single quotes

src/main/javascript/helpers/handlebars.js

@@ -9,7 +9,7 @@ Handlebars.registerHelper('sanitize', function(html) {
 
 Handlebars.registerHelper('renderTextParam', function(param) {
     var result, type = 'text', idAtt = '';
-    var paramType = param.type || param.schema.type || '';
+    var paramType = param.type ? param.type : (param.schema ? (param.schema.type ? param.schema.type : '') : '');
     var isArray = paramType.toLowerCase() === 'array' || param.allowMultiple;
     var defaultValue = isArray && Array.isArray(param.default) ? param.default.join('\n') : param.default;
 
@@ -75,4 +75,4 @@ Handlebars.registerHelper('ifCond', function (v1, operator, v2, options) {
         default:
             return options.inverse(this);
     }
-});
+});