OS 'different' Service

This service could not run because of the following error:

Undefined offset: 0 in /srv/vhosts/differentfrom.org/services/relationships/RelationshipStore.php line 339 (code 8)

#0 /srv/vhosts/differentfrom.org/services/relationships/RelationshipStore.php(339): Slim\Slim::handleErrors(8, 'Undefined offse...', '/srv/vhosts/dif...', 339, Array)
#1 /srv/vhosts/differentfrom.org/services/relationships/RelationshipService.php(193): RelationshipStore->getCanon(':symbol', 19)
#2 [internal function]: RelationshipService->getCanon(':symbol')
#3 /srv/vhosts/differentfrom.org/lib/slim/Slim/Route.php(468): call_user_func_array(Array, Array)
#4 /srv/vhosts/differentfrom.org/lib/slim/Slim/Slim.php(1355): Slim\Route->dispatch()
#5 /srv/vhosts/differentfrom.org/lib/slim/Slim/Middleware/Flash.php(85): Slim\Slim->call()
#6 /srv/vhosts/differentfrom.org/lib/slim/Slim/Middleware/MethodOverride.php(92): Slim\Middleware\Flash->call()
#7 /srv/vhosts/differentfrom.org/lib/slim/Slim/Middleware/PrettyExceptions.php(67): Slim\Middleware\MethodOverride->call()
#8 /srv/vhosts/differentfrom.org/lib/slim/Slim/Middleware/PrettyExceptions.php(67): Slim\Middleware\PrettyExceptions->call()
#9 /srv/vhosts/differentfrom.org/lib/slim/Slim/Slim.php(1300): Slim\Middleware\PrettyExceptions->call()
#10 /srv/vhosts/differentfrom.org/index.php(17): Slim\Slim->run()
#11 {main}