chm viewer unable to show contents

Question

I have a chm file that I can open at home. I use windows XP at home and at work. However, when I open the file at work it doesn't show the contents of the file. It properly shows the TOC for the file though. Any ideas pls?

Answer 1

Other than what Nicolas suggested, you may not be able to see contents of a CHM that you open over a UNC path. If that is the case copy the file to a local drive.

Answer 2

Try to right-click on your chm file and select properties. You will see an "Unblock" button. Click on it, it should solve your problem.

Answer 3

just go to power shell and run it as administrator, cd your folder

and use the following command Unblock-File '.\filename.chm'

Answer 4

I had the same situation, on a Windows 10 (VMware) system. I had to move the file to a local drive as suggested by another poster AND THEN uncheck the file opening warning message. Opening the file gave a "Open File - Security Warning" message, with a checkbox at the bottom "Always ask before opening this file". Until I unchecked that box, only the TOC showed. After unchecking, the contents showed properly. HTH someone else!

Answer 5

On Windows 7 copying the file locally and unchecking the file opening warning message worked.

Answer 6

Open command prompt and run as administrator. Go to file location, input the file name and press enter. It should open the file and view contents in chm viewer.

More read at: http://langbasics.blogspot.in/2014/12/chm-viewer-unable-to-show-contents.html

Thanks

Answer 7

It appears a lot of people have this problem but were unable to track down a solution. There are apparently different levels of authentication. Most articles I read tell you to set the MaxAllowedZone to '1' which means that local machine zone and intranet zone are allowed but '4' allows access for 'all' zones.

For more info, read this article: https://support.microsoft.com/en-us/kb/892675

This is how my registry looks (I wasn't sure it would work with the wild cards but it seems to work for me):

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\HTMLHelp]

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\HTMLHelp\1.x]

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\HTMLHelp\1.x\ItssRestrictions]
"MaxAllowedZone"=dword:00000004

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\HTMLHelp\1.x\ItssRestrictions]
"UrlAllowList"="\\\\<network_path_root>;\\\\<network_path_root>\*;\\ies-inc.local;http://www.*;http://*;https://www.*;https://*;"

As an additional note, weirdly the "UrlAllowList" key was required to make this work on another PC but not my test one. It's probably not required at all but when I added it, it fixed the problem. The user may have not closed the original file or something like that. So just a consideration. I suggest try the least and test it, then add if needed. Once you confirm, you can deploy if needed. If the 'Unblock' method does not work, or you do not see the option, this should. Good Luck!

P.S. Another method that worked was mapping the path to the network locally by using mklink /d (symbolic linking in Windows 7 or newer) but mapping a network drive letter (Z: for testing) did not work. Just food for thought and I did not have to 'Unblock' any files. Also the accepted 'Solution' did not resolve the issue for me.

Answer 8

Your CHM File Has the "#" Hash Character in the Filename or in the Directory Name. Please remove "#" and you will be able to see the content. If still you are not able to see then please visit following link: https://www.helpsmith.com/chm-cannot-be-displayed.php

Answer 9

I had same problem and zipped the file then open it from inside the zip program.(I use 7-zip)

Answer 10

If someone need, there is a web page: http://topdf.com/ where is possible convert a chm in to pdf. I tested it with a chm of ~18MB and 615 pages. I was able to got a pdf with a hyperlinked contents table.

Answer 11

I was experiencing the same problem. I read that the .chm file only worked on NTFS. My file was on a cloud network drive which is not NTFS, so I copied it locally and the problem was gone.

Answer 12

Use SumatraPDF. It opens .chm files.