BCUninstaller/Bulk-Crap-Uninstaller · warning · InvalidOperationException

Process has no MainModule

Error message

Process has no MainModule

What it means

Thrown by the window-targeting feature when the user drags the crosshair onto a window and the targeted process's MainModule resolves to null. Process.MainModule is null when the caller cannot enumerate the target's modules (typically a bitness mismatch, insufficient privilege, or the process having exited). BCU catches it and shows a generic error dialog.

Source

Thrown at source/BulkCrapUninstaller/Forms/Helpers/TargetWindow.cs:68

            DialogResult = DialogResult.OK;
            Close();
            DirectoriesSelected?.Invoke(this, e);
        }

        private void WindowTargeter1OnPickingStarted(object sender, EventArgs e)
        {
            _setMainWindowVisible(false);
        }

        private void WindowTargeterWindowSelected(object sender, Klocman.Subsystems.WindowHoverEventArgs e)
        {
            _setMainWindowVisible(true);

            try
            {
                var fileName = e.TargetWindow.GetRunningProcess().MainModule?.FileName;
                if (fileName == null)
                    throw new InvalidOperationException("Process has no MainModule");

                var parentDirectory = new FileInfo(fileName).Directory;
                if (parentDirectory == null)
                    throw new InvalidOperationException("Failed to get MainModule Directory");

                // Ignore targeting BCU itself
                if (PathTools.SubPathIsInsideBasePath(Program.AssemblyLocation.FullName, fileName, true, true))
                    return;

                OnDirectoriesSelected(new DirectoriesSelectedEventArgs(parentDirectory.ToEnumerable().ToList()));
            }
            catch (Exception exception)
            {
                Console.WriteLine(exception);
                PremadeDialogs.GenericError(exception);
            }
        }

View on GitHub (pinned to 608321de98)

Solutions

1. Run BCU as administrator so it can inspect the target process modules.
2. Use the BCU build that matches the OS architecture (x64 BCU on x64 Windows).
3. Target a different window whose process is still running and inspectable.
4. Browse to the directory manually instead of using the window targeter.

try { var fileName = proc.MainModule?.FileName; /* ... */ }
catch (InvalidOperationException) { /* inform user, skip target */ }

When it happens

Trigger: Targeting a 64-bit system process from 32-bit BCU (or vice versa); targeting a process running at higher integrity (e.g. a service); targeting a window whose process exited between hover and selection; targeting a UWP/store app.

Common situations: Running non-elevated BCU against an elevated app; using the x86 BCU build on x64 Windows against svchost/System; targeting store apps.

Related errors

• Could not close running instance of Regedit
• Failed to get MainModule Directory
• Failed to call the API
• Process name can't be null or empty
• regedit.exe failed to execute properly

AI-assisted analysis of BCUninstaller/Bulk-Crap-Uninstaller@608321de98 (2026-08-13). Data as JSON: /api/errors/aa2517134b4db165. Report an issue: GitHub.