I’ve reviewed the diagnostic report but there was nothing obviously untoward in it. The error message itself was not present in any of the diagnostic logs; I am wondering if it may have been presented by a different process rather than the Keyman process itself? It’s hard to say for sure because while the message itself is not one that is present in Keyman, it could be present in the Windows Installer.
From here, it’s hard to know what to investigate further; if the issue is reproducible we could shadow you with TeamViewer and capture further diagnostics when the error arises. Up to you!