Getting Return code 1618 when trying to run a post-installation task.
The Error code 1618 comes from the Operating System and means, "Another installation is already in progress," indicates that a previous installation process is still running, preventing a new installation from starting.
The error code 1618 arises when the Windows Installer service (msiexec.exe) is already in use by another installation or update.
Only one MSI-based installation can run at a time on a Windows system.
This can occur even if the OS is not showing an active installation window.
To resolve this:
Change the post-installation task order, or add a reboot before running the post-installation task needed. A reboot can clear any lingering installation processes.
