What causes "{0} {1} not successful." in chocolatey/choco?

Check the log output for the specific uninstaller error — the Error-level log before this exception explains what went wrong.

chocolatey/choco · error · ApplicationException

{0} {1} not successful.

Error message

{0} {1} not successful.

What it means

Thrown as an ApplicationException during HandlePackageUninstallResult when packageResult.Success is false after an uninstall attempt. This explicitly stops the NuGet service from continuing with package removal — it is a hard failure that propagates up. The message formats the package name and 'uninstall' as the operation.

Source

Thrown at src/chocolatey/infrastructure.app/services/ChocolateyPackageService.cs:1560

                HandleFailedOperation(config, packageResult, movePackageToFailureLocation: true, attemptRollback: true);
            }

            if (_rebootExitCodes.Contains(packageResult.ExitCode))
            {
                if (config.Features.ExitOnRebootDetected)
                {
                    Environment.ExitCode = ApplicationParameters.ExitCodes.ErrorInstallSuspend;
                    this.Log().Warn(ChocolateyLoggers.Important, @"Chocolatey has detected a pending reboot after uninstalling
package '{0}' - stopping further execution".FormatWith(packageResult.Name));

                    throw new ApplicationException("Reboot required before continuing. Reboot and run the same command again.");
                }
            }

            if (!packageResult.Success)
            {
                // throw an error so that NuGet Service doesn't attempt to continue with package removal
                throw new ApplicationException("{0} {1} not successful.".FormatWith(packageResult.Name, "uninstall"));
            }
        }

        private void UninstallCleanup(ChocolateyConfiguration config, PackageResult packageResult)
        {
            if (config.Features.RemovePackageInformationOnUninstall)
            {
                _packageInfoService.Remove(packageResult.PackageMetadata);
            }

            EnsureBadPackagesPathIsClean(packageResult);
            RemoveBackupIfExists(packageResult);
            HandleExtensionPackages(config, packageResult);
            HandleTemplatePackages(config, packageResult);
            HandleHookPackages(config, packageResult);

            if (config.Force)
            {

View on GitHub (pinned to 0d5abdd10c)

Solutions

Check the log output for the specific uninstaller error — the Error-level log before this exception explains what went wrong.
Use --force to bypass exit code checks: 'choco uninstall pkg -y --force'.
Close applications that may be locking the package files before uninstalling.
Manually remove leftover files from the package directory in the lib folder if the uninstaller partially completed.

Example fix

// before: uninstall fails due to locked files or exit code
choco uninstall mypackage -y

// after: force removal, or close locking processes first
choco uninstall mypackage -y --force
// or manually clean up
Remove-Item -Recurse -Force $env:ChocolateyInstall\lib\mypackage

Defensive patterns

Strategy: try-catch

Validate before calling

// Before uninstall, verify the package is installed and not locked
foreach (var name in config.PackageNames.Split(';'))
{
    var pkgDir = _fileSystem.CombinePaths(ApplicationParameters.PackagesLocation, name);
    if (!_fileSystem.DirectoryExists(pkgDir))
    {
        throw new InvalidOperationException($"Package '{name}' is not installed locally.");
    }
}

Try / catch

try
{
    _packageService.Uninstall(config);
}
catch (ApplicationException ex) when (ex.Message.Contains("not successful"))
{
    // The specific package and 'uninstall' are in the message
    logger.Error($"Uninstall failed: {ex.Message}");
    // Optionally retry with --force or clean up manually
    logger.Info("Try: choco uninstall <pkg> -y --force");
}

Prevention

Close all applications that may be locking package files before uninstalling.
Use --force to bypass exit code validation when the uninstaller leaves non-critical artifacts.
Check the log output for the specific uninstaller error before this exception.
Manually remove the package directory from the lib folder if the uninstaller partially completed.

When it happens

Trigger: Inside HandlePackageUninstallResult, after checking reboot exit codes, the code checks packageResult.Success. If false (the uninstaller reported failure, non-zero exit code, or an error occurred), this exception is thrown unconditionally — there is no feature flag to skip it, unlike the StopOnFirstPackageFailure flow.

Common situations: An uninstaller returns a non-zero exit code (not a reboot code), a chocolateyUninstall.ps1 script errors out, or files are locked preventing removal. The error message follows the pattern '{packageName} uninstall not successful.'

Related errors

AI-assisted analysis of chocolatey/choco@0d5abdd10c (2026-08-13). Data as JSON: /api/errors/a5060811cd03cf66. Report an issue: GitHub.