diff --git a/CHANGELOG.md b/CHANGELOG.md
index 085526ce1fbe6755e60aef5c08794e23d530d9d7..e936d2032060d8931259de3770a3382e9e2ebcac 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,6 +17,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+* Unknown error when trying to access the user list.
+  [linkahead-server#250](https://gitlab.com/linkahead/linkahead-server/-/issues/250)
 * Legacy integer ids are incremented by 1 again, not by 2.
 
 ### Security
diff --git a/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLListUsers.java b/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLListUsers.java
index 3b68c45d0ff60473ae837f3c9ebc17ae82e68c2d..db00b1d310e636dca4c96973d3578f6ee0400369 100644
--- a/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLListUsers.java
+++ b/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLListUsers.java
@@ -54,7 +54,7 @@ public class MySQLListUsers extends MySQLTransaction implements ListUsersImpl {
           user.realm = rs.getString("realm");
           user.email = rs.getString("email");
           user.entity = rs.getString("entity");
-          if (user.entity.isBlank() || user.entity.equals("0")) {
+          if (user.entity == null || user.entity.isBlank() || user.entity.equals("0")) {
             user.entity = null;
           }
           user.status = UserStatus.valueOf(rs.getString("status"));