Route "entity.spamicide.add_form" does not exist

Problem/Motivation

Installed via composer, trying to activate in /extend, but it gives this;

The website encountered an unexpected error. Please try again later.

Symfony\Component\Routing\Exception\RouteNotFoundException: Route "entity.spamicide.add_form" does not exist. in Drupal\Core\Routing\RouteProvider->getRouteByName() (line 208 of core/lib/Drupal/Core/Routing/RouteProvider.php).

Drupal\Core\Routing\UrlGenerator->getRoute() (Line: 271)
Drupal\Core\Routing\UrlGenerator->generateFromRoute() (Line: 105)
Drupal\Core\Render\MetadataBubblingUrlGenerator->generateFromRoute() (Line: 762)
Drupal\Core\Url->toString() (Line: 182)
Drupal\Core\Utility\LinkGenerator->generate() (Line: 95)
Drupal\Core\Render\Element\Link::preRenderLink()
call_user_func_array() (Line: 100)
Drupal\Core\Render\Renderer->doTrustedCallback() (Line: 781)
Drupal\Core\Render\Renderer->doCallback() (Line: 372)
Drupal\Core\Render\Renderer->doRender() (Line: 444)
Drupal\Core\Render\Renderer->doRender() (Line: 444)
Drupal\Core\Render\Renderer->doRender() (Line: 200)
Drupal\Core\Render\Renderer->render() (Line: 226)
Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}() (Line: 573)
Drupal\Core\Render\Renderer->executeInRenderContext() (Line: 227)
Drupal\Core\Render\MainContent\HtmlRenderer->prepare() (Line: 117)
Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse() (Line: 90)
Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray() (Line: 78)
Symfony\Component\EventDispatcher\LegacyEventDispatcherProxy->dispatch() (Line: 163)
Symfony\Component\HttpKernel\HttpKernel->handleRaw() (Line: 80)
Symfony\Component\HttpKernel\HttpKernel->handle() (Line: 57)
Drupal\Core\StackMiddleware\Session->handle() (Line: 47)
Drupal\Core\StackMiddleware\KernelPreHandle->handle() (Line: 106)
Drupal\page_cache\StackMiddleware\PageCache->pass() (Line: 85)
Drupal\page_cache\StackMiddleware\PageCache->handle() (Line: 57)
Drupal\advban\AdvbanMiddleware->handle() (Line: 50)
Drupal\ban\BanMiddleware->handle() (Line: 47)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle() (Line: 52)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle() (Line: 49)
Drupal\remove_http_headers\StackMiddleware\RemoveHttpHeadersMiddleware->handle() (Line: 23)
Stack\StackedHttpKernel->handle() (Line: 705)
Drupal\Core\DrupalKernel->handle() (Line: 19)

After which I have to uninstall via drush.