OrchardCMS/OrchardCore · error · NotSupportedException

The syntax isn't supported for SetPropertyTask.

Error message

The syntax {Syntax} isn't supported for SetPropertyTask.

What it means

SetPropertyTask computes the value to write into workflowContext.Properties by switching on the activity's Syntax. Only Liquid (LiquidValue) and JavaScript (Value) evaluation are implemented; any other WorkflowScriptSyntax value falls to the default arm and throws NotSupportedException, so the workflow property is never set.

Solutions

  1. Set Syntax to WorkflowScriptSyntax.Liquid and supply the value in the LiquidValue expression field.
  2. Or set Syntax to WorkflowScriptSyntax.JavaScript and provide the value in the Value field.
  3. Correct the stored workflow definition if it contains an obsolete syntax value.
  4. If a new syntax member exists in the enum, update/rebuild OrchardCore.Workflows so the switch arm is implemented.

Example fix

// before
var task = new SetPropertyTask(); // Syntax unset -> throws
// after
var task = new SetPropertyTask
{
    Syntax = WorkflowScriptSyntax.JavaScript,
    PropertyName = "LastRun",
    Value = new JavaScriptExpression { Expression = "new Date().toISOString()" }
};
Defensive patterns

Strategy: validation

Validate before calling

// before executing the task
if (setPropertyTask.Syntax is not (WorkflowScriptSyntax.Liquid or WorkflowScriptSyntax.JavaScript))
    throw new InvalidOperationException($"SetPropertyTask requires Liquid or JavaScript syntax; got {setPropertyTask.Syntax}");

Type guard

static bool IsSupportedSyntax(WorkflowScriptSyntax s) => s is WorkflowScriptSyntax.Liquid or WorkflowScriptSyntax.JavaScript;

Try / catch

try { result = await task.ExecuteAsync(workflowContext, activityContext); }
catch (NotSupportedException ex) { logger.LogError(ex, "SetPropertyTask evaluation failed for syntax {Syntax}", syntax); /* mark property unset */ }

Prevention

When it happens

Trigger: Executing a SetPropertyTask whose Syntax property is not WorkflowScriptSyntax.Liquid or WorkflowScriptSyntax.JavaScript — an unset/default enum value, an unrecognized syntax string deserialized from workflow JSON, or programmatic creation without assigning Syntax.

Common situations: Workflow definitions imported from other environments carrying stale syntax names; a newly added WorkflowScriptSyntax member unsupported by SetPropertyTask; missing Syntax assignment when constructing the activity in code or tests.

Related errors

AI-assisted analysis of OrchardCMS/OrchardCore@4306c0717f (2026-09-13). Data as JSON: /api/errors/39f91fc9bb1ec266. Report an issue: GitHub.

Appendix: source

Thrown at src/OrchardCore.Modules/OrchardCore.Workflows/Activities/SetPropertyTask.cs:61

        set => SetProperty(value);
    }

    public WorkflowScriptSyntax Syntax
    {
        get => GetProperty(() => WorkflowScriptSyntax.JavaScript);
        set => SetProperty(value);
    }

    public override IEnumerable<Outcome> GetPossibleOutcomes(WorkflowExecutionContext workflowContext, ActivityContext activityContext)
        => Outcome(S["Done"]);

    public override async Task<ActivityExecutionResult> ExecuteAsync(WorkflowExecutionContext workflowContext, ActivityContext activityContext)
    {
        var value = Syntax switch
        {
            WorkflowScriptSyntax.Liquid => await _expressionEvaluator.EvaluateAsync(LiquidValue, workflowContext, null),
            WorkflowScriptSyntax.JavaScript => await _scriptEvaluator.EvaluateAsync(Value, workflowContext),
            _ => throw new NotSupportedException($"The syntax {Syntax} isn't supported for SetPropertyTask.")
        };

        workflowContext.Properties[PropertyName] = value;

        return Outcome("Done");
    }
}

View on GitHub (pinned to 4306c0717f)