Issue

tool_dispatch.ntool is missing from Nessus on Windows.

PS & .\nessuscli.exe
Error: Can not find C:\ProgramData\Tenable\Nessus\nessus\tools\tool_dispatch.ntool.  Please check that Nessus is installed properly.

Cause

C:\ProgramData\Tenable\Nessus\nessus\tools\tool_dispatch.ntool doesn't actually exist.

Solution

Backup, uninstall and re-install Nessus. The .msi (for version 8.15.2) does not allow repair.

1. Backup/rename C:\ProgramData\Tenable.
2. Uninstall Nessus.
3. Re-install Nessus. Accept that it wants to clear the C:\ProgramData\Tenable\Nessus directory.
4. Stop the Nessus service.
5. Yoink Nessus\nessus\tools\tool_dispatch.ntool from the fresh install to your original/renamed/backed-up install directory.
6. Restore your original Tenable directory .
7. Start the Nessus service.