diff --git a/src/components/catalog/catalog.riot b/src/components/catalog/catalog.riot
index 4d051846..9861ba1d 100644
--- a/src/components/catalog/catalog.riot
+++ b/src/components/catalog/catalog.riot
@@ -69,6 +69,7 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
         state.registryUrl = props.registryUrl;
         let repositories = [];
         const self = this;
+        const catalogUrl = `${props.registryUrl}/v2/_catalog?n=${state.catalogElementsLimit}`;
         const oReq = new Http({
           onAuthentication: this.props.onAuthentication,
         });
@@ -93,7 +94,7 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
               return acc;
             }, []);
           } else if (this.status === 404) {
-            self.props.onNotify('Server not found', true);
+            self.props.onNotify({ code: 'CATALOG_NOT_FOUND', url: catalogUrl }, true);
           } else {
             self.props.onNotify(this.responseText);
           }
@@ -109,7 +110,7 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
             loadend: true,
           });
         });
-        oReq.open('GET', `${props.registryUrl}/v2/_catalog?n=${state.catalogElementsLimit}`);
+        oReq.open('GET', catalogUrl);
         oReq.send();
       },
     };
diff --git a/src/components/dialogs/confirm-delete-image.riot b/src/components/dialogs/confirm-delete-image.riot
index 4aaa57ec..06410302 100644
--- a/src/components/dialogs/confirm-delete-image.riot
+++ b/src/components/dialogs/confirm-delete-image.riot
@@ -109,9 +109,13 @@
           'application/vnd.docker.distribution.manifest.v2+json, application/vnd.oci.image.manifest.v1+json'
         );
         oReq.addEventListener('error', function () {
+          const credMsg = this.withCredentials
+            ? ' When you use credentials on a different hostname, the registry server may fail preflight requests. Check FAQ and issue #104.'
+            : '';
           onNotify({
             message:
-              "An error occurred when deleting image. Check if your server accept DELETE methods Access-Control-Allow-Methods: ['DELETE'].",
+              "An error occurred when deleting image. Check if your server accept DELETE methods Access-Control-Allow-Methods: ['DELETE']." +
+              credMsg,
             isError: true,
           });
         });
diff --git a/src/components/docker-registry-ui.riot b/src/components/docker-registry-ui.riot
index a84b786f..bee1f7b5 100644
--- a/src/components/docker-registry-ui.riot
+++ b/src/components/docker-registry-ui.riot
@@ -80,6 +80,13 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
       on-authenticated="{ state.onAuthenticated }"
       opened="{ state.authenticationDialogOpened }"
     ></registry-authentication>
+    <error-page
+      if="{ state.pageError }"
+      code="{ state.pageError.code }"
+      status="{ state.pageError.status }"
+      message="{ state.pageError.message }"
+      url="{ state.pageError.url }"
+    ></error-page>
     <material-snackbar message="{ state.snackbarMessage }" is-error="{ state.snackbarIsError }"></material-snackbar>
   </main>
   <footer>
@@ -105,6 +112,7 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
     import TagHistory from './tag-history/tag-history.riot';
     import DialogsMenu from './dialogs/dialogs-menu.riot';
     import SearchBar from './search-bar.riot';
+    import ErrorPage from './error-page.riot';
     import { stripHttps, getRegistryServers, setRegistryServers, truthy, stringToArray } from '../scripts/utils';
     import router from '../scripts/router';
     import { loadTheme } from '../scripts/theme';
@@ -118,6 +126,7 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
         SearchBar,
         Router,
         Route,
+        ErrorPage,
       },
       onUpdated(props, state) {
         state.snackbarIsError = false;
@@ -184,6 +193,11 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
             snackbarMessage: message,
             snackbarIsError: isError || false,
           });
+        } else if (message && message.code) {
+          this.update({
+            pageError: message,
+          });
+          setTimeout(() => delete this.state['pageError'], 1000);
         } else if (message && message.message) {
           this.update({
             snackbarMessage: message.message,
diff --git a/src/components/error-page.riot b/src/components/error-page.riot
new file mode 100644
index 00000000..03ec7215
--- /dev/null
+++ b/src/components/error-page.riot
@@ -0,0 +1,69 @@
+<error-page>
+  <div class="content">
+    <h1 if="{ getStatusCode() }">{ getStatusCode() }</h1>
+    <h2>{ props.code }</h2>
+    <template if="{ props.code === 'CATALOG_NOT_FOUND' }">
+      <p>We received a 404 status code from your registry.</p>
+      <p>The contact point was <a href="{ props.url }">{ props.url }</a></p>
+      <p>
+        This may be caused by a misconfiguration of Docker Registry UI. Check the
+        <a href="https://joxit.dev/docker-registry-ui/#faq">FAQ</a> and
+        <a href="https://joxit.dev/docker-registry-ui/#available-options">Available options</a>
+      </p>
+    </template>
+    <template if="{ props.code === 'MIXED_CONTENT' }">
+      <p>
+        <span>Mixed Content</span>: The page at `<a href="{ window.location.origin }">{ window.location.origin }</a>`
+        was loaded over HTTPS, but requested an insecure server endpoint `<a href="{ new URL(props.url).origin }"
+          >{ new URL(props.url).origin }</a
+        >`.
+      </p>
+      <p>This request <span>may</span> has been blocked; the content must be served over HTTPS.</p>
+      <p>
+        You may unset the option `<span>REGISTRY_URL</span>` and set the registry server container URL in
+        `<span>NGINX_PROXY_PASS_URL</span>`. It's usually the name of your container, and it should be on the shame
+        network as the UI.
+      </p>
+      <p>You can check the issue <a href="/~https://github.com/Joxit/docker-registry-ui/issues/277">#277</a>.</p>
+    </template>
+    <template if="{ props.code === 'INCORRECT_URL' }">
+      <p>`{ props.url }` does not seems to be a correct URL, should starts with http:// or https://.</p>
+    </template>
+  </div>
+  <script>
+    export default {
+      getStatusCode() {
+        const { props } = this;
+        switch (props.code) {
+          case 'CATALOG_NOT_FOUND':
+            return '404';
+        }
+      },
+      URL: window.URL,
+    };
+  </script>
+  <style>
+    :host {
+      display: flex;
+      flex-direction: row;
+      margin-top: 20px;
+    }
+    :host .content {
+      margin: auto;
+      text-align: center;
+    }
+    :host .content a {
+      color: var(--accent-text);
+    }
+    :host .content a:visited {
+      color: var(--accent-text);
+    }
+    :host .content p span {
+      color: var(--accent-text);
+      font-weight: 700;
+    }
+    :host .content h2 {
+      font-weight: 700;
+    }
+  </style>
+</error-page>
diff --git a/src/scripts/http.js b/src/scripts/http.js
index 432fb730..d6c3c9b3 100644
--- a/src/scripts/http.js
+++ b/src/scripts/http.js
@@ -71,7 +71,7 @@ export class Http {
                 req.withCredentials = true;
               }
               req.hasHeader = hasHeader;
-              req.getErrorMessage = Http.getErrorMessage;
+              req.getErrorMessage = getErrorMessage;
               self.oReq = req;
               req.send();
             });
@@ -128,15 +128,9 @@ const hasHeader = function (header) {
 
 const getErrorMessage = function () {
   if (this._url.match('^http://') && window.location.protocol === 'https:') {
-    return (
-      'Mixed Content: The page at `' +
-      window.location.origin +
-      '` was loaded over HTTPS, but requested an insecure server endpoint `' +
-      new URL(this._url).origin +
-      '`. This request has been blocked; the content must be served over HTTPS.'
-    );
+    return { code: 'MIXED_CONTENT', url: this._url };
   } else if (!this._url || !this._url.match('^http')) {
-    return 'Incorrect server endpoint.';
+    return { code: 'INCORRECT_URL', url: this._url };
   } else if (this.withCredentials && !this.hasHeader('Access-Control-Allow-Credentials')) {
     return (
       "The `Access-Control-Allow-Credentials` header in the response is missing and must be set to `true` when the request's credentials mode is on. Origin `" +