peass-ng/PEASS-ng · error · ArgumentOutOfRangeException

A task must be registered with at least one action and no mo

Error message

A task must be registered with at least one action and no more than 32 actions.

What it means

RegisterTaskDefinition validates that the task definition has between 1 and 32 actions and throws ArgumentOutOfRangeException otherwise. The Windows Task Scheduler requires at least one action per registered task and caps actions at 32.

Source

Thrown at winPEAS/winPEASexe/winPEAS/TaskScheduler/TaskFolder.cs:484

        /// 
        /// // Create an action that will launch Notepad whenever the trigger fires
        /// td.Actions.Add("notepad.exe", "c:\\test.log");
        /// 
        /// // Register the task in the root folder of the local machine using the current user and the S4U logon type
        /// TaskService.Instance.RootFolder.RegisterTaskDefinition("Test", td);
        /// ]]></code>
        /// <para>This example registers that same task using the SYSTEM account.</para>
        /// <code lang="cs"><![CDATA[
        /// TaskService.Instance.RootFolder.RegisterTaskDefinition("TaskName", taskDefinition, TaskCreation.CreateOrUpdate, "SYSTEM", null, TaskLogonType.ServiceAccount);
        /// ]]></code>
        /// <para>This example registers that same task using a specific username and password along with a security definition.</para>
        /// <code lang="cs"><![CDATA[
        /// TaskService.Instance.RootFolder.RegisterTaskDefinition("TaskName", taskDefinition, TaskCreation.CreateOrUpdate, "userDomain\\userName", "userPassword", TaskLogonType.Password, @"O:BAG:DUD:(A;ID;0x1f019f;;;BA)(A;ID;0x1f019f;;;SY)(A;ID;FA;;;BA)(A;;FR;;;BU)");
        /// ]]></code></example>
        public Task RegisterTaskDefinition([NotNull] string path, [NotNull] TaskDefinition definition, TaskCreation createType, string userId, string password = null, TaskLogonType logonType = TaskLogonType.S4U, string sddl = null)
        {
            if (definition.Actions.Count < 1 || definition.Actions.Count > 32)
                throw new ArgumentOutOfRangeException(nameof(definition.Actions), @"A task must be registered with at least one action and no more than 32 actions.");

            userId ??= definition.Principal.Account;
            if (userId == string.Empty) userId = null;
            User user = new User(userId);
            if (v2Folder != null)
            {
                definition.Actions.ConvertUnsupportedActions();
                if (logonType == TaskLogonType.ServiceAccount)
                {
                    if (string.IsNullOrEmpty(userId) || !user.IsServiceAccount)
                        throw new ArgumentException(@"A valid system account name must be supplied for TaskLogonType.ServiceAccount. Valid entries are ""NT AUTHORITY\SYSTEM"", ""SYSTEM"", ""NT AUTHORITY\LOCALSERVICE"", or ""NT AUTHORITY\NETWORKSERVICE"".", nameof(userId));
                    if (password != null)
                        throw new ArgumentException(@"A password cannot be supplied when specifying TaskLogonType.ServiceAccount.", nameof(password));
                }
                /*else if ((LogonType == TaskLogonType.Password || LogonType == TaskLogonType.InteractiveTokenOrPassword ||
					(LogonType == TaskLogonType.S4U && UserId != null && !user.IsCurrent)) && password == null)
				{
					throw new ArgumentException("A password must be supplied when specifying TaskLogonType.Password or TaskLogonType.InteractiveTokenOrPassword or TaskLogonType.S4U from another account.", nameof(password));

View on GitHub (pinned to 53fb989abc)

Solutions

1. Add at least one action, e.g. definition.Actions.Add(new ExecAction("cmd.exe", "/c script")), before registering
2. Split tasks exceeding 32 actions into multiple registered tasks or chained tasks
3. Validate definition.Actions.Count in [1,32] before calling RegisterTaskDefinition

Example fix

// before
var td = ts.NewTask();
// forgot to add an action
rootFolder.RegisterTaskDefinition("MyTask", td);
// after
var td = ts.NewTask();
td.Actions.Add(new ExecAction("notepad.exe"));
rootFolder.RegisterTaskDefinition("MyTask", td);

if (definition.Actions.Count < 1 || definition.Actions.Count > 32) throw new InvalidOperationException("Task must have 1-32 actions");

try { root.RegisterTaskDefinition(name, td); }
catch (ArgumentOutOfRangeException ex) when (ex.ParamName == "definition.Actions") { /* add/split actions */ }

When it happens

Trigger: Calling RegisterTaskDefinition (directly or via RegisterTask) with a TaskDefinition whose Actions collection is empty, or programmatically appending more than 32 actions.

Common situations: Building a TaskDefinition without calling Actions.Add (forgot to add an ExecAction); loops that batch-generate tasks and exceed the 32-action cap; merging action lists from configuration without bounding them.

Related errors

• On systems prior to Windows 10, all individual parameters mu
• The array and none of the values passed as parameters may be
• A maximum of 32 parameters can be supplied to RunEx.
• On systems prior to Windows 10, no individual parameter may
• Specified argument was out of the range of valid values. (Pa

AI-assisted analysis of peass-ng/PEASS-ng@53fb989abc (2026-09-02). Data as JSON: /api/errors/7ad54baa98fd2997. Report an issue: GitHub.