There currently is a bug in v2.13 for the code generator for single record section editors.
In a single record editor only, when an admin tries to access the Code Generator using the Advanced Options drop down menu at the bottom of the record, this bug sends you into the General Settings area instead.
This doesn't seem to affect multi-record editors and there are no issues with going straight to the Code Generator from the Admin Section Editors area.
Here is the fix I received from Damon Edis (thank you):
To fix it, open this file:
/cmsAdmin/lib/menus/default/edit.php
On line 91 and 92 replace with this:
if ($CURRENT_USER['isAdmin']) { $advancedCommands['Admin: Edit Section'] = '?menu=database&action=editTable&tableName=' . urlencode($tableName); }
if ($CURRENT_USER['isAdmin']) { $advancedCommands['Admin:: Code Generator'] = '?menu=admin&action=generator&tableName=' . urlencode($tableName); }
Basically it is replacing "&" with just "&".