I get the same thing though.
Set this in your LocalSettings.php to show better errors:
error_reporting( -1 );
ini_set( 'display_errors', 1 );
$wgShowExceptionDetails = true;
$wgShowDBErrorBacktrace = true;
More verbose error reporting shows this:
[XMsiOxY1GBxqYnzCqifKOgAAAAA] /index.php?title=Special:UserLogin&returnto=Main+Page Error from line 388 of /var/www/html/extensions/LdapAuth/src/Auth/PrimaryAuthenticationProvider.php: Class 'Symfony\Component\Ldap\Ldap' not found
Backtrace:
#0 /var/www/html/extensions/LdapAuth/src/Auth/PrimaryAuthenticationProvider.php(110): Shanept\LdapAuth\Auth\PrimaryAuthenticationProvider->connect(Shanept\LdapAuth\Auth\LdapAuthenticationRequest)
#1 /var/www/html/extensions/LdapAuth/src/Auth/PrimaryAuthenticationProvider.php(88): Shanept\LdapAuth\Auth\PrimaryAuthenticationProvider->beginPrimaryLdapAuthentication(Shanept\LdapAuth\Auth\LdapAuthenticationRequest)
#2 /var/www/html/includes/auth/AuthManager.php(453): Shanept\LdapAuth\Auth\PrimaryAuthenticationProvider->beginPrimaryAuthentication(array)
#3 /var/www/html/includes/auth/AuthManager.php(383): MediaWiki\Auth\AuthManager->continueAuthentication(array)
#4 /var/www/html/includes/specialpage/AuthManagerSpecialPage.php(353): MediaWiki\Auth\AuthManager->beginAuthentication(array, string)
#5 /var/www/html/includes/specialpage/AuthManagerSpecialPage.php(482): AuthManagerSpecialPage->performAuthenticationStep(string, array)
#6 /var/www/html/includes/htmlform/HTMLForm.php(665): AuthManagerSpecialPage->handleFormSubmit(array, VFormHTMLForm)
#7 /var/www/html/includes/specialpage/AuthManagerSpecialPage.php(416): HTMLForm->trySubmit()
#8 /var/www/html/includes/specialpage/LoginSignupSpecialPage.php(317): AuthManagerSpecialPage->trySubmit()
#9 /var/www/html/includes/specialpage/SpecialPage.php(569): LoginSignupSpecialPage->execute(NULL)
#10 /var/www/html/includes/specialpage/SpecialPageFactory.php(568): SpecialPage->run(NULL)
#11 /var/www/html/includes/MediaWiki.php(288): MediaWiki\Special\SpecialPageFactory->executePath(Title, RequestContext)
#12 /var/www/html/includes/MediaWiki.php(860): MediaWiki->performRequest()
#13 /var/www/html/includes/MediaWiki.php(517): MediaWiki->main()
#14 /var/www/html/index.php(42): MediaWiki->run()
#15 {main}