abpframework/abp · error · CliUsageException

Project name cannot be "{illegalProjectName}"! Specify a dif

Error message

Project name cannot be "{illegalProjectName}"! Specify a different name.

What it means

Thrown by ProjectNameValidator.ValidateIllegalProjectName when the project name exactly equals (case-insensitive) one of the reserved/template names: MyCompanyName.MyProjectName, MyProjectName, or Windows device names CON, AUX, PRN, COM1, LPT2. These names are blocked because they are either unmodified template placeholders or invalid Windows filenames.

Source

Thrown at framework/src/Volo.Abp.Cli.Core/Volo/Abp/Cli/Utils/ProjectNameValidator.cs:47

            throw new CliUsageException("Project name cannot contain \"..\"! Specify a different name.");
        }
    }

    private static void ValidateSurrogateOrControlChar(string projectName)
    {
        if (projectName.Any(chr => char.IsControl(chr) || char.IsSurrogate(chr)))
        {
            throw new CliUsageException("Project name cannot contain surrogate or control characters! Specify a different name.");
        }
    }

    private static void ValidateIllegalProjectName(string projectName)
    {
        foreach (var illegalProjectName in IllegalProjectNames)
        {
            if (projectName.Equals(illegalProjectName, StringComparison.OrdinalIgnoreCase))
            {
                throw new CliUsageException("Project name cannot be \"" + illegalProjectName + "\"! Specify a different name.");
            }
        }
    }

    private static void ValidateIllegalKeywords(string projectName)
    {
        foreach (var illegalKeyword in IllegalKeywords)
        {
            if (projectName.Split(".").Contains(illegalKeyword))
            {
                throw new CliUsageException("Project name cannot contain the word \"" + illegalKeyword + "\". Specify a different name.");
            }
        }
    }

    public static void Validate(string projectName)
    {
        ValidateSurrogateOrControlChar(projectName);

View on GitHub (pinned to 7ed43b1931)

Solutions

Choose a real, unique project name (e.g. Acme.BookStore) instead of the template placeholder.
Avoid Windows device names (CON, AUX, PRN, COM1-9, LPT1-9) regardless of OS for portability.
If generating programmatically, validate the candidate name with ProjectNameValidator.Validate() first.

Example fix

// before
abp new MyProjectName
abp new CON

// after
abp new Acme.BookStore
abp new Acme.ConsoleApp

Defensive patterns

Strategy: validation

Validate before calling

static readonly HashSet<string> Reserved = new(StringComparer.OrdinalIgnoreCase)
{ "MyCompanyName.MyProjectName","MyProjectName","CON","AUX","PRN","COM1","LPT2" };
static void EnsureNotReserved(string name)
{
    if (Reserved.Contains(name)) throw new ArgumentException($"'{name}' is reserved/invalid");
    Volo.Abp.Cli.Utils.ProjectNameValidator.Validate(name);
}

Prevention

Never use the template placeholder as the final name.
Avoid Windows device names for portability.
Validate candidate names with ProjectNameValidator before CLI invocation.

When it happens

Trigger: Running `abp new MyProjectName` or `abp new CON` without renaming from the template default, or using a Windows-reserved device name.

Common situations: Forgetting to rename the default template placeholder; scripting `abp new` with the literal example name; choosing a name that collides with a Windows device name and would fail to create a directory on Windows.

Related errors

AI-assisted analysis of abpframework/abp@7ed43b1931 (2026-08-13). Data as JSON: /api/errors/5e66de34d9a46b0d. Report an issue: GitHub.