app/application/resources/site/js/_choose-documentation-version.js

@@ -1,8 +1,10 @@
 let blockDocumentationVersion = document.querySelector('#documentation-version');
-blockDocumentationVersion.querySelector('.documentation-version__button').addEventListener('click', (e) => {
+if (blockDocumentationVersion) {
+    blockDocumentationVersion.querySelector('.documentation-version__button').addEventListener('click', (e) => {
         if (blockDocumentationVersion.classList.contains('active')) {
             blockDocumentationVersion.classList.remove('active');
         } else {
             blockDocumentationVersion.classList.add('active');
         }
-});
+    });
+}