diff --git a/.github/workflows/phpstan.yml b/.github/workflows/phpstan.yml
index b5772ef711..d43788bb2a 100644
--- a/.github/workflows/phpstan.yml
+++ b/.github/workflows/phpstan.yml
@@ -22,6 +22,7 @@ jobs:
           path: webapp/src webapp/tests
           php_extensions: gd intl mysqli pcntl zip
           autoload_file: webapp/vendor/autoload.php
+          version: composer
       - uses: actions/upload-artifact@v4
         if: always()
         with:
diff --git a/webapp/src/Command/ImportEventFeedCommand.php b/webapp/src/Command/ImportEventFeedCommand.php
index 4b1960059b..f8060805c4 100644
--- a/webapp/src/Command/ImportEventFeedCommand.php
+++ b/webapp/src/Command/ImportEventFeedCommand.php
@@ -223,10 +223,12 @@ protected function compareContestId(): bool
         $ourId   = $contest->getExternalid();
         $theirId = $this->sourceService->getContestId();
         if ($ourId !== $theirId) {
-            $this->style->error(
+            $this->style->warning(
                 "Contest ID in external system $theirId does not match external ID in DOMjudge ($ourId)."
             );
-            return false;
+            if (!$this->style->confirm('Do you want to continue anyway?', default: false)) {
+                return false;
+            }
         }
 
         return true;
diff --git a/webapp/src/DataTransferObject/ApiInfo.php b/webapp/src/DataTransferObject/ApiInfo.php
index 17a8f5ed56..b5a08c0528 100644
--- a/webapp/src/DataTransferObject/ApiInfo.php
+++ b/webapp/src/DataTransferObject/ApiInfo.php
@@ -7,8 +7,8 @@
 class ApiInfo
 {
     public function __construct(
-        public readonly string $version,
-        public readonly string $versionUrl,
+        public readonly ?string $version,
+        public readonly ?string $versionUrl,
         public readonly string $name,
         public readonly ?ApiInfoProvider $provider,
         #[Serializer\Exclude(if: '!object.domjudge')]
diff --git a/webapp/src/DataTransferObject/Shadowing/ProblemEvent.php b/webapp/src/DataTransferObject/Shadowing/ProblemEvent.php
index 7c5b76d348..95a1701e8e 100644
--- a/webapp/src/DataTransferObject/Shadowing/ProblemEvent.php
+++ b/webapp/src/DataTransferObject/Shadowing/ProblemEvent.php
@@ -7,7 +7,7 @@ class ProblemEvent implements EventData
     public function __construct(
         public readonly string $id,
         public readonly string $name,
-        public readonly float $timeLimit,
+        public readonly ?float $timeLimit,
         public readonly ?string $label,
         public readonly ?string $rgb,
     ) {}
diff --git a/webapp/src/Service/ExternalContestSourceService.php b/webapp/src/Service/ExternalContestSourceService.php
index f50ccee457..3d0212d523 100644
--- a/webapp/src/Service/ExternalContestSourceService.php
+++ b/webapp/src/Service/ExternalContestSourceService.php
@@ -1027,9 +1027,12 @@ protected function validateAndUpdateProblem(Event $event, EventData $data): void
 
         $toCheckProblem = [
             'name'      => $data->name,
-            'timelimit' => $data->timeLimit,
         ];
 
+        if ($data->timeLimit) {
+            $toCheckProblem['timelimit'] = $data->timeLimit;
+        }
+
         if ($contestProblem->getShortname() !== $data->label) {
             $this->logger->warning(
                 'Contest problem short name does not match between feed (%s) and local (%s), updating',
@@ -1097,7 +1100,10 @@ protected function validateAndUpdateTeam(Event $event, EventData $data): void
         if (!empty($data->organizationId)) {
             $affiliation = $this->em->getRepository(TeamAffiliation::class)->findOneBy(['externalid' => $data->organizationId]);
             if (!$affiliation) {
+                // Affiliation does not exist. Create one with a dummy name so we can continue.
                 $affiliation = new TeamAffiliation();
+                $affiliation->setName($data->organizationId);
+                $affiliation->setShortname(substr($data->organizationId, 0, 32));
                 $this->em->persist($affiliation);
             }
             $team->setAffiliation($affiliation);
@@ -1106,7 +1112,9 @@ protected function validateAndUpdateTeam(Event $event, EventData $data): void
         if (!empty($data->groupIds[0])) {
             $category = $this->em->getRepository(TeamCategory::class)->findOneBy(['externalid' => $data->groupIds[0]]);
             if (!$category) {
+                // Category does not exist. Create one with a dummy name so we can continue.
                 $category = new TeamCategory();
+                $category->setName($data->groupIds[0]);
                 $this->em->persist($category);
             }
             $team->setCategory($category);