When logged on as an admin user and attempting to select a normal logged on user in the masquerade block, the site locks up. In order to get back in I have to delete Masquerade from the server, reboot and clear my browser cache.

I am using Organic Groups

I checked "site admin" in permissions for
administer masquerade and
masquerade as user

On the Masquerade setting page
I checked site admin for Roles that are considered "administrators" for masquerading:

I did not set anything for Menu Quick Switch user: or Masquerade Block Quick Switch users:

I got this error repeated over and over in the logs
access denied
User MyRegularLoggedInUser
Location http://www.mysite.org/admin/build/modules

I also got this error in the log
call_user_func_array() [function.call-user-func-array]: First argument is expected to be a valid callback, 'masquerade_access' was given in /var/www/DCr22beta/profiles/drupal_commons/modules/contrib/og_features/og_features.module on line 512.

OG Features is weighted at 100
I changed OG weight from 0 to 1, but that did not help

Comments

This does not happen if I first safely navigate to a non-administrative part of the site.

So, I can get around it that way.

I would expect it to fail by simply saying
Access denied
You are not authorized to access this page.

instead of locking up