Some times when we access few CHM (compiled HTML) files over network share, CHM content doed not display and shows an error "The Page Can not be displayed".
This may be due to a Microsoft security update installed on your machine. Here is the resolution:-
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REGEDIT4
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\HTMLHelp]
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\HTMLHelp\1.x\HHRestrictions]
"MaxAllowedZone"=dword:00000001
"UrlAllowList"=""
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\HTMLHelp\1.x\ItssRestrictions]
"MaxAllowedZone"=dword:00000001
"UrlAllowList"=""
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Put above content in a file and save as with .REG extension, then execute it from your machine.
Thats it.. you should be able to view your CHM files.
Reference