diff --git a/lib/Controller/LocalController.php b/lib/Controller/LocalController.php
index 96b1cd5ec..614428719 100644
--- a/lib/Controller/LocalController.php
+++ b/lib/Controller/LocalController.php
@@ -36,6 +36,7 @@
 use OCA\Circles\Exceptions\FederatedUserNotFoundException;
 use OCA\Circles\Exceptions\FrontendException;
 use OCA\Circles\Exceptions\InvalidIdException;
+use OCA\Circles\Exceptions\MemberNotFoundException;
 use OCA\Circles\Exceptions\RequestBuilderException;
 use OCA\Circles\Exceptions\SingleCircleNotFoundException;
 use OCA\Circles\Model\FederatedUser;
@@ -273,10 +274,13 @@ public function membersAdd(string $circleId, array $members): DataResponse {
 			$federatedUsers = [];
 			foreach ($members as $member) {
 				// TODO: generate Multiple FederatedUsers using a single SQL request
-				$federatedUsers[] = $this->federatedUserService->generateFederatedUser(
-					$this->get('id', $member),
-					$this->getInt('type', $member)
-				);
+				try {
+					$federatedUsers[] = $this->federatedUserService->generateFederatedUser(
+						$this->get('id', $member),
+						$this->getInt('type', $member)
+					);
+				} catch (MemberNotFoundException) {
+				}
 			}
 
 			$result = $this->memberService->addMembers($circleId, $federatedUsers);
diff --git a/lib/Service/FederatedUserService.php b/lib/Service/FederatedUserService.php
index d69914a86..e91b00b2b 100644
--- a/lib/Service/FederatedUserService.php
+++ b/lib/Service/FederatedUserService.php
@@ -778,6 +778,10 @@ public function getFederatedUser(string $federatedId, int $type = Member::TYPE_S
 	 * @return FederatedUser
 	 */
 	public function generateFederatedUser(string $federatedId, int $type = 0): FederatedUser {
+		if ($federatedId === '') {
+			throw new MemberNotFoundException('empty user id');
+		}
+
 		if ($type === Member::TYPE_MAIL) {
 			$federatedId = strtolower($federatedId);
 		}