Remote Desktop Manager -- Installation failed.

On two systems I am having difficulties installing the new version. Runs through the setup then rolls back. The resulting old install is unstable and freezes regularly.

Event viewer is no help only showing the message

"Ending a Windows Installer transaction: C:\Users\sadyer\AppData\Roaming\Devolutions inc\Remote Desktop Manager\install\Setup.RemoteDesktopManager.12.6.4.0.msi. Client Process Id: 4620."

then

"Remote Desktop Manager -- Installation failed."

then

"Windows Installer installed the product. Product Name: Remote Desktop Manager. Product Version: 12.6.4.0. Product Language: 1033. Manufacturer: Devolutions inc.. Installation success or error status: 0."

Any help would be appreciated.