diff --git a/scripts/content-search-filtering.js b/scripts/content-search-filtering.js
index 95076c7..94cd063 100644
--- a/scripts/content-search-filtering.js
+++ b/scripts/content-search-filtering.js
@@ -143,10 +143,15 @@ function mountToTopOfSearchResults(element) {
           document.querySelector('#topstuff')?.prepend(element);
         } else if (document.querySelector('#main')) {
           var el = document.querySelector('#main');
-          if (el.querySelector('#main > div[data-hveid]')) {
-            el.insertBefore(element, el.querySelector('div[data-hveid]'));
-          } else {
-            el.insertBefore(element, el.querySelector('div div[data-hveid]').parentElement);
+          if (el) {
+            if (el.querySelector('#main > div[data-hveid]')) {
+              el.insertBefore(element, el.querySelector('div[data-hveid]'));
+            } else {
+              const hveid = el.querySelector('div div[data-hveid]');
+              if (hveid) {
+                el.insertBefore(element, hveid.parentElement);
+              }
+            }
           }
         }
         break;
@@ -199,8 +204,15 @@ function mountToTopOfSearchResults(element) {
         document.querySelector('#main')?.prepend(element);
         break;
       default:
-    }
-  };
+  }
+
+  // Return whether element was successfully mounted
+  if (element.id && document.querySelector(element.id)) {
+    return true;
+  } else {
+    return false;
+  }
+};
 
 /**
  * Shows a banner at the top of the search results page for a given wiki type, if one is not already present.
@@ -242,7 +254,7 @@ function mountSearchBanner(wikiInfo) {
 
     /** @param {MouseEvent & { target: HTMLDivElement, currentTarget: HTMLDivElement }} e */
     showResultsButton.onclick = function (e) {
-      if (e.target.textContent.includes(extensionAPI.i18n.getMessage('searchFilteredResultsShow'))) {
+      if (e.target.textContent?.includes(extensionAPI.i18n.getMessage('searchFilteredResultsShow'))) {
         e.target.textContent = extensionAPI.i18n.getMessage('searchFilteredResultsHide');
         hiddenWikisRevealed[elementId] = true;
         const selector = e.currentTarget.dataset.group;
@@ -356,7 +368,7 @@ function getResultContainer(searchEngine, searchResult) {
     case 'qwant':
       if (searchResult.closest('div[data-testid=webResult]')) {
         const cssQuery = 'div[data-testid=webResult]';
-        searchResultContainer = searchResult.closest(cssQuery).parentElement;
+        searchResultContainer = searchResult.closest(cssQuery)?.parentElement;
       }
       break;
     case 'startpage':
@@ -653,10 +665,10 @@ function filterAnchors(newAnchors) {
                 // Extract the URL between "RU=" and "/RK="
                 const embeddedUrlRegex = /RU=([^/]+)\/RK=/;
                 const match = searchResult.href.match(embeddedUrlRegex);
-                const extractedURL = decodeURIComponent(match && match[1]);
-
-                if (extractedURL) searchResult.setAttribute('data-iwb-href', extractedURL);
-
+                if (match) {
+                  const extractedURL = decodeURIComponent(match && match[1]);
+                  if (extractedURL) searchResult.setAttribute('data-iwb-href', extractedURL);
+                }
               } catch (e) {
                 console.error('Indie Wiki Buddy failed to parse Yahoo link with error: ', e);
               }
@@ -676,13 +688,13 @@ function filterAnchors(newAnchors) {
     default: {
       if (storage.customSearchEngines) {
         function filterSearXNG() {
-          const searchResults = newAnchors.filter(e => e.matches('h3>a'));
-          filterSearchResults(searchResults);
+          const searchResults = newAnchors?.filter(e => e.matches('h3>a'));
+          if (searchResults) filterSearchResults(searchResults);
         }
 
         function filterWhoogle() {
-          const searchResults = newAnchors.filter(e => e.matches('div>a'));
-          filterSearchResults(searchResults);
+          const searchResults = newAnchors?.filter(e => e.matches('div>a'));
+          if (searchResults) filterSearchResults(searchResults);
         }
 
         /** @param {string} searchEngine */
@@ -716,7 +728,9 @@ function checkRevalidate() {
     pageChangeDetector.id = 'iwb-page-change-detector';
     pageChangeDetector.style.display = 'none';
     try {
-      mountToTopOfSearchResults(pageChangeDetector);
+      /** @type {boolean} */
+      const containerMounted = mountToTopOfSearchResults(pageChangeDetector);
+      if (!containerMounted) return;
       // just in case, re-process search results
       console.debug('IWB: Reprocessing search results...');
       filterAnchors(Array.from(document.body?.querySelectorAll('a')));
@@ -736,11 +750,17 @@ function filterMutations(mutations, observer) {
   if (document.body == undefined || mutations == undefined) return;
   checkRevalidate();
 
-
   const addedSubtrees = mutations.flatMap(mutation => Array.from(mutation.addedNodes));
   const newAnchors = /** @type {HTMLAnchorElement[]} */ (addedSubtrees
     .filter(node => node instanceof HTMLElement)
-    .flatMap(node => (isAnchor(node) && node) || Array.from(node.querySelectorAll('a')))
+    .flatMap(node => {
+      if (isAnchor(node)) {
+        return node;
+      } else if (node instanceof HTMLElement) {
+        return Array.from(node.querySelectorAll('a'));
+      }
+      return [];
+    })
   );
 
   filterAnchors(newAnchors);