diff --git a/src/shared/components/Contentful/SearchBar/SearchBar.jsx b/src/shared/components/Contentful/SearchBar/SearchBar.jsx
index 3fe97914e3..ab0abb9e09 100644
--- a/src/shared/components/Contentful/SearchBar/SearchBar.jsx
+++ b/src/shared/components/Contentful/SearchBar/SearchBar.jsx
@@ -379,12 +379,13 @@ export class SearchBarInner extends Component {
    * Update suggestion list with new search text
    * This function use debounce delay to avoid processing or requesting too much
    *
-   * @param {String} searchText Search text
+   * @param {String} searchTerm Search text
    */
-  updateSuggestionListWithNewSearch(searchText) {
+  updateSuggestionListWithNewSearch(searchTerm) {
     const {
       selectedFilter,
     } = this.state;
+    const searchText = searchTerm ? encodeURIComponent(searchTerm) : '';
 
     if (searchText) {
       const query = {
@@ -499,6 +500,7 @@ export class SearchBarInner extends Component {
           <IconSearch className={theme['icon-search']} />
           <input
             value={inputlVal}
+            maxLength={115}
             ref={this.setSearchFieldRef}
             type="text"
             placeholder="Search..."
diff --git a/src/shared/containers/EDU/Tracks.jsx b/src/shared/containers/EDU/Tracks.jsx
index db827da600..c56164f40d 100644
--- a/src/shared/containers/EDU/Tracks.jsx
+++ b/src/shared/containers/EDU/Tracks.jsx
@@ -84,6 +84,16 @@ export default class EDUTracks extends React.Component {
         ? urlQuery.tags : (urlQuery.tags ? [urlQuery.tags] : []);
       if (urlQuery.startDate) urlQuery.startDate = moment(urlQuery.startDate).format();
       if (urlQuery.endDate) urlQuery.endDate = moment(urlQuery.endDate).format();
+      // validate track string in URL query
+      // set CP if missing or wrong
+      const tracks = _.keys(TRACK_BANNER_BACK_COLORS);
+      if (!urlQuery.track || _.indexOf(tracks, urlQuery.track) === -1) {
+        urlQuery.track = 'Competitive Programming';
+        updateQuery({
+          ...query,
+          ...urlQuery,
+        });
+      }
       this.setState({
         query: {
           ...query,
@@ -96,6 +106,27 @@ export default class EDUTracks extends React.Component {
     // Get the EDU taxonomy
     this.apiService.getEDUTaxonomy()
       .then((taxonomy) => {
+        if (urlQuery.tax) {
+          // check if tax exists or is wrong
+          const foundSome = _.some(
+            _.flatten(
+              _.values(taxonomy),
+            ), cat => cat.name.toLowerCase() === urlQuery.tax.toLowerCase(),
+          );
+          if (!foundSome) {
+            delete urlQuery.tax;
+            updateQuery({
+              ...query,
+              ...urlQuery,
+            });
+            this.setState({
+              query: {
+                ...query,
+                ...urlQuery,
+              },
+            });
+          }
+        }
         const tree = tracksTreeBuilder(taxonomy, urlQuery);
         this.setState({
           tree,
diff --git a/src/shared/services/contentful.js b/src/shared/services/contentful.js
index ded9dacaf7..81b7dd1e1c 100644
--- a/src/shared/services/contentful.js
+++ b/src/shared/services/contentful.js
@@ -316,12 +316,10 @@ class Service {
       // thus we need to find it first
       await this.queryEntries({
         content_type: 'person',
-        query: author,
+        query: encodeURIComponent(author),
       })
         .then((result) => {
-          if (result.total) {
-            query['fields.contentAuthor.sys.id'] = result.items[0].sys.id;
-          }
+          query['fields.contentAuthor.sys.id'] = result.total ? result.items[0].sys.id : 'NO_SUCH_ID';
         });
     }
     if (tax && track && taxonomy && taxonomy[track]) {
@@ -335,19 +333,19 @@ class Service {
           }
         });
       } else {
-        const taxId = _.find(taxonomy[track], ['name', tax]).id;
-        taxIDs.push(taxId);
+        const taxId = _.find(taxonomy[track], ['name', tax]);
+        if (taxId) taxIDs.push(taxId.id);
       }
       if (taxIDs.length) query['fields.contentCategory.sys.id[in]'] = taxIDs.join(',');
     }
     if (track) query['fields.trackCategory'] = track;
     if (!_.isEmpty(tags)) {
-      query['fields.tags[all]'] = tags.join(',');
+      query['fields.tags[all]'] = tags.map(t => encodeURIComponent(t)).join(',');
     }
     if (startDate) query['fields.creationDate[gte]'] = startDate;
     if (endDate) query['fields.creationDate[lte]'] = endDate;
-    if (phrase) query.query = phrase;
-    if (title) query['fields.title[match]'] = title;
+    if (phrase) query.query = encodeURIComponent(phrase);
+    if (title) query['fields.title[match]'] = encodeURIComponent(title);
     if (sortBy) {
       switch (sortBy) {
         case 'Likes': query.order = '-fields.upvotes,-fields.creationDate'; break;