diff --git a/DataLayer/ExtraAuthClasses/ModulesForUser.cs b/DataLayer/ExtraAuthClasses/ModulesForUser.cs
index 4a53f6a..6122c19 100644
--- a/DataLayer/ExtraAuthClasses/ModulesForUser.cs
+++ b/DataLayer/ExtraAuthClasses/ModulesForUser.cs
@@ -13,6 +13,11 @@ namespace DataLayer.ExtraAuthClasses
     /// </summary>
     public class ModulesForUser : IChangeEffectsUser, IAddRemoveEffectsUser
     {
+        /// <summary>
+        /// Empty constructor for migration to work.
+        /// </summary>
+        private ModulesForUser() { }
+
         /// <summary>
         /// This links modules to a user
         /// </summary>
diff --git a/DataLayer/ExtraAuthClasses/RoleToPermissions.cs b/DataLayer/ExtraAuthClasses/RoleToPermissions.cs
index 38f0fbc..1daa993 100644
--- a/DataLayer/ExtraAuthClasses/RoleToPermissions.cs
+++ b/DataLayer/ExtraAuthClasses/RoleToPermissions.cs
@@ -69,7 +69,7 @@ public static IStatusGeneric<RoleToPermissions> CreateRoleWithPermissions(string
         public void Update(string description, ICollection<Permissions> permissions)
         {
             if (permissions == null || !permissions.Any())
-                throw new InvalidOperationException("There should be at least one permission associated with a role.");
+                throw new ArgumentException("There should be at least one permission associated with a role.", nameof(permissions));
 
             _permissionsInRole = permissions.PackPermissionsIntoString();
             Description = description;
diff --git a/DataLayer/ExtraAuthClasses/UserToRole.cs b/DataLayer/ExtraAuthClasses/UserToRole.cs
index be4ed87..6918b6e 100644
--- a/DataLayer/ExtraAuthClasses/UserToRole.cs
+++ b/DataLayer/ExtraAuthClasses/UserToRole.cs
@@ -39,6 +39,7 @@ public UserToRole(string userId, RoleToPermissions role)
 
         public static IStatusGeneric<UserToRole> AddRoleToUser(string userId, string roleName, ExtraAuthorizeDbContext context)
         {
+            if (userId == null) throw new ArgumentNullException(nameof(userId));
             if (roleName == null) throw new ArgumentNullException(nameof(roleName));
 
             var status = new StatusGenericHandler<UserToRole>();