Clear Cache - First content edit

Warning: file_get_contents(/libraries/contents/plugin.js): failed to open stream: No such file or directory in _locale_parse_js_file() (line 1131 of core/modules/locale/locale.module).
_locale_parse_js_file('/libraries/contents/plugin.js') (Line: 543)
locale_js_translate(Array) (Line: 305)
Drupal\ckeditor\Plugin\Editor\CKEditor->getJSSettings(Object) (Line: 81)
Drupal\editor\Plugin\EditorManager->getAttachments(Array) (Line: 92)
Drupal\editor\Element->preRenderTextFormat(Array)
call_user_func(Array, Array) (Line: 378)
Drupal\Core\Render\Renderer->doRender(Array, ) (Line: 195)
Drupal\Core\Render\Renderer->render(Array) (Line: 490)
Drupal\Core\Template\TwigExtension->escapeFilter(Object, Array, 'html', NULL, 1) (Line: 81)
__TwigTemplate_98360c133351f86c9c3ad73c8c67ad64d30fa101e86683f7e236ff6c3c754c0f->doDisplay(Array, Array) (Line: 432)
Twig_Template->displayWithErrorHandling(Array, Array) (Line: 403)
Twig_Template->display(Array) (Line: 411)
Twig_Template->render(Array) (Line: 64)
twig_render_template('core/themes/classy/templates/form/field-multiple-value-form.html.twig', Array) (Line: 384)
Drupal\Core\Theme\ThemeManager->render('field_multiple_value_form', Array) (Line: 437)
Drupal\Core\Render\Renderer->doRender(Array) (Line: 450)
Drupal\Core\Render\Renderer->doRender(Array) (Line: 450)
Drupal\Core\Render\Renderer->doRender(Array) (Line: 450)
Drupal\Core\Render\Renderer->doRender(Array) (Line: 450)
Drupal\Core\Render\Renderer->doRender(Array, ) (Line: 195)
Drupal\Core\Render\Renderer->render(Array) (Line: 490)
Drupal\Core\Template\TwigExtension->escapeFilter(Object, Array, 'html', NULL, 1) (Line: 47)
__TwigTemplate_bd2e9fb546babd2fc90475216fa09b863e6ca963e76dfd8edbab66ec1cb7fcb3->doDisplay(Array, Array) (Line: 432)
Twig_Template->displayWithErrorHandling(Array, Array) (Line: 403)
Twig_Template->display(Array) (Line: 411)
Twig_Template->render(Array) (Line: 64)
twig_render_template('core/themes/seven/templates/node-edit-form.html.twig', Array) (Line: 384)
Drupal\Core\Theme\ThemeManager->render('node_edit_form', Array) (Line: 437)
Drupal\Core\Render\Renderer->doRender(Array, ) (Line: 195)
Drupal\Core\Render\Renderer->render(Array, ) (Line: 226)
Drupal\Core\Render\MainContent\HtmlRenderer->Drupal\Core\Render\MainContent\{closure}() (Line: 582)
Drupal\Core\Render\Renderer->executeInRenderContext(Object, Object) (Line: 227)
Drupal\Core\Render\MainContent\HtmlRenderer->prepare(Array, Object, Object) (Line: 117)
Drupal\Core\Render\MainContent\HtmlRenderer->renderResponse(Array, Object, Object) (Line: 90)
Drupal\Core\EventSubscriber\MainContentViewSubscriber->onViewRenderArray(Object, 'kernel.view', Object)
call_user_func(Array, Object, 'kernel.view', Object) (Line: 111)
Drupal\Component\EventDispatcher\ContainerAwareEventDispatcher->dispatch('kernel.view', Object) (Line: 156)
Symfony\Component\HttpKernel\HttpKernel->handleRaw(Object, 1) (Line: 68)
Symfony\Component\HttpKernel\HttpKernel->handle(Object, 1, 1) (Line: 57)
Drupal\Core\StackMiddleware\Session->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\KernelPreHandle->handle(Object, 1, 1) (Line: 99)
Drupal\page_cache\StackMiddleware\PageCache->pass(Object, 1, 1) (Line: 78)
Drupal\page_cache\StackMiddleware\PageCache->handle(Object, 1, 1) (Line: 47)
Drupal\Core\StackMiddleware\ReverseProxyMiddleware->handle(Object, 1, 1) (Line: 52)
Drupal\Core\StackMiddleware\NegotiationMiddleware->handle(Object, 1, 1) (Line: 23)
Stack\StackedHttpKernel->handle(Object, 1, 1) (Line: 666)
Drupal\Core\DrupalKernel->handle(Object) (Line: 19)

I found that the leading slash was causing the issue, e.g. "(/libraries/contents/plugin.js)" would throw the warning but "libraries/contents/plugin.js)" did not.

All functionality seems to work in either case - regardless of the warning or the leading slash.