Error - Help System

In response to increasing security problems involving Help files (.CHM extension), Microsoft recently introduced Security Update 896358. The security update prevents CHM files from opening unless those files reside locally on the user's hard drive. After the update is installed, users who access MASC from a server or network location will not be able to open the Help and will receive the messages "Action canceled" or "The page cannot be displayed".

To alleviate this issue, please refer to Microsoft Knowledge Base ID 896054, below. We have tested this solution and recommend that you use Method 1: Modify the ItssRestrictions registry entry to enable a specific Web application, which is located under the Consumers and non-enterprise customers section of the article:

1. Click Start, click Run, type regedit, and then click OK.

2. Locate and then click the following subkey:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\HTMLHelp\1.x\ItssRestrictions

Note: If this registry subkey does not exist, create it. To do this, follow these steps:
a. On the Edit menu, point to New, and then click Key.
b. Type ItssRestrictions, and then press [ENTER].

3. Right-click the ItssRestrictions subkey, point to New, and then click String Value.

4. Type UrlAllowList, and then press [ENTER].

5. Right-click the UrlAllowList value, and then click Modify.

6. In the Value data box, type the path to the application that you want to enable, and then click OK.

Notes:
• Entries in the UrlAllowList value are separated by a semicolon.

• If you access the application through a UNC path, you must add two entries corresponding to the UNC path, as in the following examples:
For MASC:
\\servername\PathToMASC\;file://\\servername\PathToMASC

Note: In the example above, use the word "file"; do not substitute a filename. 


• Or, if you access the application through a mapped drive, you must add two entries corresponding to the drive letter, as in the following examples:
For MASC:
driveletter:\PathToMASC\;file://driveletter:\PathToMASC

7. Quit Registry Editor.

8. Re-start MASC.