TypeError: 'NoneType' object is unsubscriptable

[mteredes]

How to Reproduce

While doing a GET operation on /ticket/7079, Trac issued an internal error.

(please provide additional details here)

Request parameters:

{'id': u'7079'}

User agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:20.0) Gecko/20100101 Firefox/20.0

System Information

System information not available

Enabled Plugins

Plugin information not available

Python Traceback

Traceback (most recent call last):
  File "/usr/lib/python2.6/site-packages/Trac-0.12.2-py2.6.egg/trac/web/main.py", line 511, in _dispatch_request
    dispatcher.dispatch(req)
  File "/usr/lib/python2.6/site-packages/Trac-0.12.2-py2.6.egg/trac/web/main.py", line 237, in dispatch
    resp = chosen_handler.process_request(req)
  File "/usr/lib/python2.6/site-packages/Trac-0.12.2-py2.6.egg/trac/ticket/web_ui.py", line 169, in process_request
    return self._process_ticket_request(req)
  File "/usr/lib/python2.6/site-packages/Trac-0.12.2-py2.6.egg/trac/ticket/web_ui.py", line 454, in _process_ticket_request
    req.perm('ticket', id, version).require('TICKET_VIEW')
  File "/usr/lib/python2.6/site-packages/Trac-0.12.2-py2.6.egg/trac/perm.py", line 575, in require
    if not self._has_permission(action, resource):
  File "/usr/lib/python2.6/site-packages/Trac-0.12.2-py2.6.egg/trac/perm.py", line 567, in _has_permission
    check_permission(action, perm.username, resource, perm)
  File "/usr/lib/python2.6/site-packages/Trac-0.12.2-py2.6.egg/trac/perm.py", line 454, in check_permission
    perm)
  File "/snc/trac/projects/spc/plugins/SNC_authorization.py", line 140, in check_permission
    self.read_access_level(username)
  File "/snc/trac/projects/spc/plugins/SNC_authorization.py", line 50, in read_access_level
    is_site_admin = (row[0] == 1)
TypeError: 'NoneType' object is unsubscriptable

[anonymous]

 Warning:

    Error with navigation contributor "ImportModule"
    Error with navigation contributor "QueryModule"
    Error with navigation contributor "BrowserModule"
    Error with navigation contributor "AdminModule"
    Error with navigation contributor "SearchModule"
    Error with navigation contributor "ReportModule"
    Error with navigation contributor "RoadmapModule"
    Error with navigation contributor "TicketModule"
    Error with navigation contributor "TimelineModule"
    Error with navigation contributor "WikiModule"

[Remy Blank]

PluginIssue (SNC_authorization.py).