Internal error

From Zaslowya Project

Detected bug in an extension! Hook efGPManagerRevokeRights failed to return a value; should return true to continue hook processing or false to abort.

Backtrace:

#0 /home/zaslavl/public_html/wiki/includes/User.php(1938): wfRunHooks('UserGetRights', Array)
#1 /home/zaslavl/public_html/wiki/includes/User.php(2083): User->getRights()
#2 /home/zaslavl/public_html/wiki/extensions/GroupPermissionsManager/plugins/ExtendedPermissions.php(100): User->isAllowed('edit')
#3 [internal function]: efGPManagerExtendedPermissionsGrant(Object(Title), Object(User), 'edit', false)
#4 /home/zaslavl/public_html/wiki/includes/Hooks.php(117): call_user_func_array('efGPManagerExte...', Array)
#5 /home/zaslavl/public_html/wiki/includes/Title.php(1105): wfRunHooks('userCan', Array)
#6 /home/zaslavl/public_html/wiki/includes/Title.php(995): Title->getUserPermissionsErrorsInternal('edit', Object(User), false)
#7 /home/zaslavl/public_html/wiki/includes/Title.php(967): Title->userCan('edit', false)
#8 /home/zaslavl/public_html/wiki/includes/parser/ParserCache.php(32): Title->quickUserCan('edit')
#9 /home/zaslavl/public_html/wiki/includes/parser/ParserCache.php(53): ParserCache->getKey(Object(Article), Object(User))
#10 /home/zaslavl/public_html/wiki/includes/OutputPage.php(653): ParserCache->get(Object(Article), Object(User))
#11 /home/zaslavl/public_html/wiki/includes/Article.php(806): OutputPage->tryParserCache(Object(Article), Object(User))
#12 /home/zaslavl/public_html/wiki/includes/Wiki.php(447): Article->view()
#13 /home/zaslavl/public_html/wiki/includes/Wiki.php(63): MediaWiki->performAction(Object(OutputPage), Object(Article), Object(Title), Object(User), Object(WebRequest))
#14 /home/zaslavl/public_html/wiki/index.php(114): MediaWiki->initialize(Object(Title), Object(Article), Object(OutputPage), Object(User), Object(WebRequest))
#15 {main}