Warning: Uninitialized string offset 0 in _color_luminance() (line 888 of themes/contrib/bootstrap/bootstrap.theme).
_color_luminance() (Line: 35)
bootstrap_preprocess_html() (Line: 523)
Drupal\Core\Theme\ThemeManager->invoke() (Line: 311)
Drupal\Core\Theme\ThemeManager->{closure:Drupal\Core\Theme\ThemeManager::render():293}() (Line: 340)
Drupal\Core\Theme\ThemeManager->render() (Line: 500)
Drupal\Core\Render\Renderer->doRender() (Line: 230)
Drupal\Core\Render\Renderer->render() (Line: 162)
Drupal\Core\Render\MainContent\HtmlRenderer->{closure:Drupal\Core\Render\MainContent\HtmlRenderer::renderResponse():157}() (Line: 634)
Drupal\Core\Render\Renderer::{closure:Drupal\Core\Render\Renderer::executeInRenderContext():634}()
Fiber->start() (Line: 635)
Drupal\Core\Render\Renderer->executeInRenderContext() (Line: 157)
Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse() (Line: 90)
Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray() (Line: 246)
Symfony\Component\EventDispatcher\EventDispatcher::{closure:Symfony\Component\EventDispatcher\EventDispatcher::optimizeListeners():241}() (Line: 206)
Symfony\Component\EventDispatcher\EventDispatcher->callListeners() (Line: 56)
Symfony\Component\EventDispatcher\EventDispatcher->dispatch() (Line: 188)
Symfony\Component\HttpKernel\HttpKernel->handleRaw() (Line: 76)
Symfony\Component\HttpKernel\HttpKernel->handle() (Line: 53)
Drupal\Core\StackMiddleware\Session->handle() (Line: 48)
Drupal\Core\StackMiddleware\KernelPreHandle->handle() (Line: 28)
Drupal\Core\StackMiddleware\ContentLength->handle() (Line: 118)
Drupal\page_cache\StackMiddleware\PageCache->pass() (Line: 92)
Drupal\page_cache\StackMiddleware\PageCache->handle() (Line: 48)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle() (Line: 51)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle() (Line: 53)
Drupal\Core\StackMiddleware\AjaxPageState->handle() (Line: 54)
Drupal\Core\StackMiddleware\StackedHttpKernel->handle() (Line: 745)
Drupal\Core\DrupalKernel->handle() (Line: 19)