Cannot manage footer menu I want to manage my footer menu, but I get this error:

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

Symfony\Component\Routing\Exception\RouteNotFoundException: Route "contact.site_page" does not exist. in Drupal\Core\Routing\RouteProvider-&gt;getRouteByName() (line 190 of core/lib/Drupal/Core/Routing/RouteProvider.php).
Drupal\Core\Routing\UrlGenerator-&gt;getRoute('contact.site_page') (Line: 269)
Drupal\Core\Routing\UrlGenerator-&gt;generateFromRoute('contact.site_page', Array, Array, 1) (Line: 105)
Drupal\Core\Render\MetadataBubblingUrlGenerator-&gt;generateFromRoute('contact.site_page', Array, Array, 1) (Line: 753)
Drupal\Core\Url-&gt;toString(1) (Line: 167)
Drupal\Core\Utility\LinkGenerator-&gt;generate('Contact', Object) (Line: 94)
Drupal\Core\Render\Element\Link::preRenderLink(Array)
call_user_func(Array, Array) (Line: 376)
Drupal\Core\Render\Renderer-&gt;doRender(Array) (Line: 448)
Drupal\Core\Render\Renderer-&gt;doRender(Array, ) (Line: 195)
Drupal\Core\Render\Renderer-&gt;render(Array) (Line: 490)
Drupal\Core\Template\TwigExtension-&gt;escapeFilter(Object, Array, 'html', NULL, 1) (Line: 183)
__TwigTemplate_c1bdd8f86c8cc62844cbb93f33c11d8a2e27610acf3c1abe4f7e3e1886bfcf45-&gt;doDisplay(Array, Array) (Line: 379)
Twig_Template-&gt;displayWithErrorHandling(Array, Array) (Line: 347)
Twig_Template-&gt;display(Array) (Line: 358)
Twig_Template-&gt;render(Array) (Line: 64)
twig_render_template('core/themes/classy/templates/dataset/table.html.twig', Array) (Line: 384)
Drupal\Core\Theme\ThemeManager-&gt;render('table', Array) (Line: 435)
Drupal\Core\Render\Renderer-&gt;doRender(Array) (Line: 448)
Drupal\Core\Render\Renderer-&gt;doRender(Array) (Line: 448)
Drupal\Core\Render\Renderer-&gt;doRender(Array, ) (Line: 195)
Drupal\Core\Render\Renderer-&gt;render(Array, ) (Line: 226)
Drupal\Core\Render\MainContent\HtmlRenderer-&gt;Drupal\Core\Render\MainContent\{closure}() (Line: 574)
Drupal\Core\Render\Renderer-&gt;executeInRenderContext(Object, Object) (Line: 227)
Drupal\Core\Render\MainContent\HtmlRenderer-&gt;prepare(Array, Object, Object) (Line: 117)
Drupal\Core\Render\MainContent\HtmlRenderer-&gt;renderResponse(Array, Object, Object) (Line: 90)
Drupal\Core\EventSubscriber\MainContentViewSubscriber-&gt;onViewRenderArray(Object, 'kernel.view', Object) (Line: 111)
Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher-&gt;dispatch('kernel.view', Object) (Line: 149)
Symfony\Component\HttpKernel\HttpKernel-&gt;handleRaw(Object, 1) (Line: 64)
Symfony\Component\HttpKernel\HttpKernel-&gt;handle(Object, 1, 1) (Line: 57)
Drupal\Core\StackMiddleware\Session-&gt;handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\KernelPreHandle-&gt;handle(Object, 1, 1) (Line: 99)
Drupal\page_cache\StackMiddleware\PageCache-&gt;pass(Object, 1, 1) (Line: 78)
Drupal\page_cache\StackMiddleware\PageCache-&gt;handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware-&gt;handle(Object, 1, 1) (Line: 50)
Drupal\Core\StackMiddleware\NegotiationMiddleware-&gt;handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel-&gt;handle(Object, 1, 1) (Line: 656)
Drupal\Core\DrupalKernel-&gt;handle(Object) (Line: 19)


Maybe it's caused by contact module, but I hav uninstalled it.
Yes it is because you uninstalled the contact module.  Try to install it again, then reset/delete that menu link from it and then uninstall it again.