something just went wrong 2.5.1

if any user register it will redirect to something just went wrong page

i was able to pull out an error that was given but i dont have any idea of what to do

Fatal Error in PHP.slugify();

Call to undefined function iconv()
The error occurred on or near: /home/infonewsnigeria/public_html/library/core/functions.general.php
3894: // replace non letter or digits by -
3895: $text = preg_replace('/[^\pL\d]+/u', '-', $text);
3896:
3897: // transliterate
3898: $text = iconv('utf-8', 'us-ascii//TRANSLIT', $text);
3899:
3900: // remove unwanted characters
3901: $text = preg_replace('/[^-\w]+/', '', $text);
3902:
Backtrace:
[/home/infonewsnigeria/public_html/library/core/class.form.php:786] PHP::slugify();
[/home/infonewsnigeria/public_html/applications/dashboard/views/modules/configuration.php:78] Gdn_Form->imageUploadPreview();
[/home/infonewsnigeria/public_html/library/core/class.module.php:130] PHP::include();
[/home/infonewsnigeria/public_html/library/core/class.module.php:281] Gdn_Module->fetchView();
[/home/infonewsnigeria/public_html/library/core/class.module.php:258] Gdn_Module->toString();
[/home/infonewsnigeria/public_html/applications/dashboard/views/settings/branding.php:9] Gdn_Module->render();
[/home/infonewsnigeria/public_html/library/core/class.controller.php:707] PHP::include();
[/home/infonewsnigeria/public_html/library/core/class.controller.php:1270] Gdn_Controller->fetchView();
[/home/infonewsnigeria/public_html/library/core/class.pluggable.php:210] Gdn_Controller->xRender();
[/home/infonewsnigeria/public_html/applications/dashboard/controllers/class.settingscontroller.php:554] Gdn_Pluggable->__call();
[/home/infonewsnigeria/public_html/library/core/class.dispatcher.php:833] SettingsController->branding();
[/home/infonewsnigeria/public_html/library/core/class.dispatcher.php:262] Gdn_Dispatcher->dispatchController();
[/home/infonewsnigeria/public_html/index.php:29] Gdn_Dispatcher->dispatch();

these are the error please what can i do