LMDE Mate Caja help doesn't work

[jennyc]

Please help a relative LMDE newbie

I am running LMDE with Mate desktop and I cant get access to the help system when using caja to browse my files, I get

Document Not Found
The URI ‘ghelp:user-guide?goscaja-1#goscaja-1’ does not point to a valid page.
Search for packages containing this document.

and when I click on the link "Search for packages containing this document." I get

GDBus.Error:org.freedesktop.DBus.Error.Spawn.ChildExited: Process /usr/bin/session-installer exited with status 1

jennyc