The template variable $displayName is never set before invoking the Contact/Page/View/GroupContact.tpl template.

I noticed an "Undefined array element: displayName" warning when viewing the group tab of a contact, and inserted the attached patch to debug the problem.

To fix the problem the run() function needs to retrieve the displayName somewhere before line 128 of CRM/Contact/Page/View/GroupContact.php.

Unfortunately, I don't know how to fix the problem, but here is the backtrace generated when viewing civicrm/contact/view/group?reset=1&snippet=1&cid=7188 with the attached patch in place:

[0] => Array
(
[file] => sites/all/modules/civicrm/packages/Smarty/Smarty.class.php
[line] => 1906
[function] => include
)

[1] => Array
(
[file] => sites/data.cfcmi.org/files/civicrm/templates_c/en_US/%%0C/0CB/0CBEC124%%default.tpl.php
[line] => 15
[function] => _smarty_include
[class] => Smarty
[type] => ->
[args] => Array
(
[0] => Array
(
[smarty_include_tpl_file] => CRM/Contact/Page/View/GroupContact.tpl
[smarty_include_vars] => Array
(
)

)

)

)

[2] => Array
(
[file] => sites/all/modules/civicrm/packages/Smarty/Smarty.class.php
[line] => 1906
[args] => Array
(
[0] => sites/data.cfcmi.org/files/civicrm/templates_c/en_US/%%0C/0CB/0CBEC124%%default.tpl.php
)

[function] => include
)

[3] => Array
(
[file] => sites/data.cfcmi.org/files/civicrm/templates_c/en_US/%%A0/A0D/A0D7E591%%snippet.tpl.php
[line] => 47
[function] => _smarty_include
[class] => Smarty
[type] => ->
[args] => Array
(
[0] => Array
(
[smarty_include_tpl_file] => CRM/Form/default.tpl
[smarty_include_vars] => Array
(
)

)

)

)

[4] => Array
(
[file] => sites/all/modules/civicrm/packages/Smarty/Smarty.class.php
[line] => 1263
[args] => Array
(
[0] => sites/data.cfcmi.org/files/civicrm/templates_c/en_US/%%A0/A0D/A0D7E591%%snippet.tpl.php
)

[function] => include
)

[5] => Array
(
[file] => sites/all/modules/civicrm/CRM/Core/Smarty.php
[line] => 182
[function] => fetch
[class] => Smarty
[type] => ->
[args] => Array
(
[0] => CRM/common/snippet.tpl
[1] =>
[2] =>
[3] =>
)

)

[6] => Array
(
[file] => sites/all/modules/civicrm/CRM/Core/Page.php
[line] => 173
[function] => fetch
[class] => CRM_Core_Smarty
[type] => ->
[args] => Array
(
[0] => CRM/common/snippet.tpl
)

)

[7] => Array
(
[file] => sites/all/modules/civicrm/CRM/Contact/Page/View/GroupContact.php
[line] => 128
[function] => run
[class] => CRM_Core_Page
[type] => ->
[args] => Array
(
)

)

[8] => Array
(
[file] => sites/all/modules/civicrm/CRM/Core/Invoke.php
[line] => 219
[function] => run
[class] => CRM_Contact_Page_View_GroupContact
[type] => ->
[args] => Array
(
[0] => Array
(
[0] => civicrm
[1] => contact
[2] => view
[3] => group
)

[1] =>
)

)

[9] => Array
(
[file] => sites/all/modules/civicrm/drupal/civicrm.module
[line] => 366
[function] => invoke
[class] => CRM_Core_Invoke
[type] => ::
[args] => Array
(
[0] => Array
(
[0] => civicrm
[1] => contact
[2] => view
[3] => group
)

)

)

[10] => Array
(
[function] => civicrm_invoke
[args] => Array
(
[0] => contact
[1] => view
[2] => group
)

)

[11] => Array
(
[file] => includes/menu.inc
[line] => 348
[function] => call_user_func_array
[args] => Array
(
[0] => civicrm_invoke
[1] => Array
(
[0] => contact
[1] => view
[2] => group
)

)

)

[12] => Array
(
[file] => index.php
[line] => 18
[function] => menu_execute_active_handler
[args] => Array
(
)

)