diff --git a/.gitmodules b/.gitmodules
index 251b1c8300..63619033bd 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -47,9 +47,6 @@
 [submodule "modules/ckanext-sixodp_showcasesubmit"]
 	path = ckan/ckanext/ckanext-sixodp_showcasesubmit
 	url = https://github.com/vrk-kpa/ckanext-sixodp_showcasesubmit.git
-[submodule "modules/ckanext-datarequests"]
-	path = ckan/ckanext/ckanext-datarequests
-	url = https://github.com/vrk-kpa/ckanext-datarequests.git
 [submodule "modules/ckanext-organizationapproval"]
 	path = ckan/ckanext/ckanext-organizationapproval
 	url = https://github.com/vrk-kpa/ckanext-organizationapproval.git
diff --git a/cdk/lib/ckan-stack.ts b/cdk/lib/ckan-stack.ts
index 79c7eb7baa..f30e975c17 100644
--- a/cdk/lib/ckan-stack.ts
+++ b/cdk/lib/ckan-stack.ts
@@ -152,7 +152,6 @@ export class CkanStack extends Stack {
       'dcat_json_interface',
       'csw_harvester',
       'drupal8',
-      //'datarequests',
       'ytp_organizations',
       'ytp_request',
       'hierarchy_display',
diff --git a/ckan/Dockerfile b/ckan/Dockerfile
index bfc4d4bf66..9bde570c0c 100644
--- a/ckan/Dockerfile
+++ b/ckan/Dockerfile
@@ -318,7 +318,6 @@ COPY ckanext/ckanext-ytp_request            ${EXT_DIR}/ckanext-ytp_request/
 COPY ckanext/ckanext-ytp_main               ${EXT_DIR}/ckanext-ytp_main/
 COPY ckanext/ckanext-hierarchy              ${EXT_DIR}/ckanext-hierarchy/
 COPY ckanext/ckanext-matomo                 ${EXT_DIR}/ckanext-matomo/
-COPY ckanext/ckanext-datarequests           ${EXT_DIR}/ckanext-datarequests/
 COPY ckanext/ckanext-harvest                ${EXT_DIR}/ckanext-harvest/
 COPY ckanext/ckanext-report                 ${EXT_DIR}/ckanext-report/
 COPY ckanext/ckanext-spatial                ${EXT_DIR}/ckanext-spatial/
diff --git a/ckan/ckanext/ckanext-advancedsearch/ckanext/advancedsearch/controller.py b/ckan/ckanext/ckanext-advancedsearch/ckanext/advancedsearch/controller.py
index d20b28afb1..bdceae305a 100644
--- a/ckan/ckanext/ckanext-advancedsearch/ckanext/advancedsearch/controller.py
+++ b/ckan/ckanext/ckanext-advancedsearch/ckanext/advancedsearch/controller.py
@@ -96,13 +96,13 @@ def search():
     query = get_action('package_search')(context, data_dict)
 
     json_query = json.dumps(
-        {k: v for k, v in list(params_to_dict(request.form).items()) if k != 'page' and type(v) is list and len(v[0]) > 0}
+        {k: v for k, v in list(params_to_dict(request.form).items()) if k != 'page' and isinstance(v, list) and len(v[0]) > 0}
     )
 
     filters = {
         k: v for k, v in list(params_to_dict(request.form).items()) if k != 'search_target' and k != 'search_query'
         and k != 'page' and k != 'released-before' and k != 'released-after' and k != 'updated-before'
-        and k != 'updated-after' and k != 'sort' and type(v) is list and len(v[0]) > 0
+        and k != 'updated-after' and k != 'sort' and isinstance(v, list) and len(v[0]) > 0
     }
 
     for key, value in filters.items():
diff --git a/ckan/ckanext/ckanext-datarequests b/ckan/ckanext/ckanext-datarequests
deleted file mode 160000
index 0076e25c0c..0000000000
--- a/ckan/ckanext/ckanext-datarequests
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 0076e25c0ce434687555e829441cb1f5acf89634
diff --git a/ckan/ckanext/ckanext-harvest b/ckan/ckanext/ckanext-harvest
index b251b04ecc..d83d9d71a0 160000
--- a/ckan/ckanext/ckanext-harvest
+++ b/ckan/ckanext/ckanext-harvest
@@ -1 +1 @@
-Subproject commit b251b04eccb46fb1b75ebc6488c5697460ae76e8
+Subproject commit d83d9d71a079d9526474c6263fc486e81ad3d70c
diff --git a/ckan/ckanext/ckanext-ytp_main/ckanext/ytp/cli.py b/ckan/ckanext/ckanext-ytp_main/ckanext/ytp/cli.py
index bd464acb8e..1b2a0e435c 100644
--- a/ckan/ckanext/ckanext-ytp_main/ckanext/ytp/cli.py
+++ b/ckan/ckanext/ckanext-ytp_main/ckanext/ytp/cli.py
@@ -196,13 +196,13 @@ def migrate(ctx, dryrun):
             resource['description_translated'] = {
                 original_language: resource.get('description', '') or ''
             }
-            if resource.get('temporal_granularity') and type(resource.get('temporal_granularity')) is not dict:
+            if resource.get('temporal_granularity') and not isinstance(resource.get('temporal_granularity'), dict):
                 resource['temporal_granularity'] = {
                     original_language: resource.get('temporal_granularity')
                 }
             else:
                 del resource['temporal_granularity']
-            if resource.get('update_frequency') and type(resource.get('update_frequency')) is not dict:
+            if resource.get('update_frequency') and not isinstance(resource.get('update_frequency'), dict):
                 resource['update_frequency'] = {
                     original_language: resource.get('update_frequency')
                 }
diff --git a/ckan/ckanext/ckanext-ytp_main/ckanext/ytp/dcat.py b/ckan/ckanext/ckanext-ytp_main/ckanext/ytp/dcat.py
index 18206df49a..745d21b15f 100644
--- a/ckan/ckanext/ckanext-ytp_main/ckanext/ytp/dcat.py
+++ b/ckan/ckanext/ckanext-ytp_main/ckanext/ytp/dcat.py
@@ -34,9 +34,9 @@
 
 
 def as_dict(value):
-    if type(value) is dict:
+    if isinstance(value, dict):
         return value
-    elif type(value) in (str, six.text_type):
+    elif isinstance(value, str) or isinstance(value, six.text_type):
         return as_dict(json.loads(value))
     else:
         raise ValueError()
@@ -507,7 +507,7 @@ def graph_from_dataset(self, dataset_dict, dataset_ref):
         if responsible_party:
             try:
                 custodians_data = json.loads(responsible_party)
-                custodians_data = custodians_data if type(custodians_data) is list else [custodians_data]
+                custodians_data = custodians_data if isinstance(custodians_data, list) else [custodians_data]
                 for custodian_data in custodians_data:
                     custodian = BNode()
                     g.add((custodian, RDF.type, FOAF.Agent))
diff --git a/ckan/ckanext/ckanext-ytp_main/ckanext/ytp/plugin.py b/ckan/ckanext/ckanext-ytp_main/ckanext/ytp/plugin.py
index b82604a4d1..aa2285a53c 100644
--- a/ckan/ckanext/ckanext-ytp_main/ckanext/ytp/plugin.py
+++ b/ckan/ckanext/ckanext-ytp_main/ckanext/ytp/plugin.py
@@ -494,7 +494,7 @@ def before_index(self, pkg_dict):
             prop_value = json.loads(prop_json)
             # Add for each language
             for lang in languages:
-                if type(prop_value) is dict and prop_value.get(lang):
+                if isinstance(prop_value, dict) and prop_value.get(lang):
                     prop_value[lang] = [tag for tag in {tag.lower() for tag in prop_value[lang]} if tag not in ignored_tags]
                     pkg_dict['vocab_%s_%s' % (prop_key, lang)] = [tag for tag in prop_value[lang]]
             pkg_dict[prop_key] = json.dumps(prop_value)
diff --git a/ckan/scripts/install_extensions.sh b/ckan/scripts/install_extensions.sh
index 4a75b404c3..3ded438f6d 100644
--- a/ckan/scripts/install_extensions.sh
+++ b/ckan/scripts/install_extensions.sh
@@ -22,7 +22,6 @@ pip_install "${EXT_DIR}/ckanext-ytp_request/requirements.txt"
 pip_install "${EXT_DIR}/ckanext-ytp_main/requirements.txt"
 pip_install "${EXT_DIR}/ckanext-hierarchy/requirements.txt"
 pip_install "${EXT_DIR}/ckanext-matomo/requirements.txt"
-pip_install "${EXT_DIR}/ckanext-datarequests/requirements.txt"
 pip_install "${EXT_DIR}/ckanext-harvest/requirements.txt"
 pip_install "${EXT_DIR}/ckanext-report/requirements.txt"
 pip_install "${EXT_DIR}/ckanext-spatial/requirements.txt"
@@ -57,7 +56,6 @@ pip_install "${EXT_DIR}/ckanext-ytp_request/pip-requirements.txt"
 pip_install "${EXT_DIR}/ckanext-ytp_main/pip-requirements.txt"
 pip_install "${EXT_DIR}/ckanext-hierarchy/pip-requirements.txt"
 pip_install "${EXT_DIR}/ckanext-matomo/pip-requirements.txt"
-pip_install "${EXT_DIR}/ckanext-datarequests/pip-requirements.txt"
 pip_install "${EXT_DIR}/ckanext-harvest/pip-requirements.txt"
 pip_install "${EXT_DIR}/ckanext-report/pip-requirements.txt"
 pip_install "${EXT_DIR}/ckanext-spatial/pip-requirements.txt"
@@ -92,7 +90,6 @@ pip install -e ${EXT_DIR}/ckanext-drupal8 \
     -e ${EXT_DIR}/ckanext-ytp_main \
     -e ${EXT_DIR}/ckanext-hierarchy \
     -e ${EXT_DIR}/ckanext-matomo \
-    -e ${EXT_DIR}/ckanext-datarequests \
     -e ${EXT_DIR}/ckanext-harvest \
     -e ${EXT_DIR}/ckanext-report \
     -e ${EXT_DIR}/ckanext-spatial \
@@ -130,7 +127,6 @@ pip install -e ${EXT_DIR}/ckanext-drupal8 \
 (cd ${EXT_DIR}/ckanext-advancedsearch; python setup.py compile_catalog -f)
 (cd ${EXT_DIR}/ckanext-scheming; python setup.py compile_catalog -f)
 (cd ${EXT_DIR}/ckanext-statistics; python setup.py compile_catalog -f)
-(cd ${EXT_DIR}/ckanext-datarequests; python setup.py compile_catalog -f)
 (cd ${EXT_DIR}/ckanext-matomo; python setup.py compile_catalog -f)
 (cd ${EXT_DIR}/ckanext-ytp_recommendation; python setup.py compile_catalog -f)
 (cd ${EXT_DIR}/ckanext-apis; python setup.py compile_catalog -f)
diff --git a/ckan/templates/production.ini.j2 b/ckan/templates/production.ini.j2
index d9f60e78b2..deb935fabe 100644
--- a/ckan/templates/production.ini.j2
+++ b/ckan/templates/production.ini.j2
@@ -139,8 +139,6 @@ ckanext.sixodp_showcasesubmit.recipient_emails = {{ environ('SYSADMIN_EMAIL') }}
 ckanext.ytp_recommendation.recaptcha_sitekey = {{ environ('RECAPTCHA_PUBLIC_KEY') }}
 ckanext.ytp_recommendation.recaptcha_secret = {{ environ('RECAPTCHA_PRIVATE_KEY') }}
 
-ckanext-datarequests.datarequest_notifications_admin_email = None
-
 ckanext.drupal8.site_url = {{ environ('CKAN_DRUPAL_SITE_URL') }}
 ckanext.drupal8.domain = {{ environ('DOMAIN_NAME') }},{{ environ('SECONDARY_DOMAIN_NAME') }}
 ckanext.drupal8.sysadmin_role = {{ environ('ROLES_CKAN_ADMIN') }}
diff --git a/drupal/modules/avoindata-header/src/Controller/HeaderController.php b/drupal/modules/avoindata-header/src/Controller/HeaderController.php
index 90cfda316c..9c19f6b801 100644
--- a/drupal/modules/avoindata-header/src/Controller/HeaderController.php
+++ b/drupal/modules/avoindata-header/src/Controller/HeaderController.php
@@ -3,6 +3,7 @@
 namespace Drupal\avoindata_header\Controller;
 
 use Drupal\Core\Controller\ControllerBase;
+use Drupal\Core\Url;
 use Symfony\Component\HttpFoundation\RedirectResponse;
 use Symfony\Component\HttpFoundation\Response;
 
@@ -29,7 +30,8 @@ public function header() {
     $queryParams = \Drupal::request()->query->all();
 
     if (isset($queryParams['activePath'])) {
-      \Drupal::service('path.current')->setPath($queryParams['activePath']);
+      $url = Url::fromUserInput($queryParams['activePath']);
+      \Drupal::service('path.current')->setPath($url->toString());
     }
 
     $response = new Response(\Drupal::service('renderer')->renderRoot($build));
diff --git a/drupal/modules/avoindata-header/src/Plugin/Form/SearchForm.php b/drupal/modules/avoindata-header/src/Plugin/Form/SearchForm.php
index ff857e8ebf..d49679a684 100644
--- a/drupal/modules/avoindata-header/src/Plugin/Form/SearchForm.php
+++ b/drupal/modules/avoindata-header/src/Plugin/Form/SearchForm.php
@@ -27,6 +27,9 @@ public function getFormId() {
    * {@inheritdoc}
    */
   public function buildForm(array $form, FormStateInterface $form_state) {
+    // AV-2034: Set form action explicitly to drop query parameters reliably.
+    $language = \Drupal::languageManager()->getCurrentLanguage()->getId();
+    $form['#action'] = sprintf('/%s/api/header', $language);
 
     $form['searchfilter'] = [
       '#type' => 'textfield',
@@ -56,19 +59,13 @@ public function buildForm(array $form, FormStateInterface $form_state) {
   public function submitForm(array &$form, FormStateInterface $form_state) {
     $filter = $form_state->getValue('searchfilter');
     $language = \Drupal::languageManager()->getCurrentLanguage()->getId();
-    $base_path = '/data/%s';
-
     if ($language === 'en') {
-      $base_path = sprintf($base_path, 'en_GB');
+      $language = 'en_GB';
     }
-    else {
-      $base_path = sprintf($base_path, $language);
-    }
-
-    $base_path = $base_path . '/search';
-    $base_path = $base_path . '?q=%s';
-    $redirect_path = sprintf($base_path, $form_state->getValue('search'));
-    $url = url::fromUserInput($redirect_path);
+    $path = sprintf('/data/%s/search', $language);
+    $url = url::fromUserInput($path, [
+      'query' => ['q' => $form_state->getValue('search')],
+    ]);
     $form_state->setRedirectUrl($url);
   }