If after downloading the Compax3 help files (.chm) which are a Microsoft Help File format and are to get an error of "Navigation to the webpage was canceled" when opening:
To fix this, navigate to the .chm file on the computer.
Default location is...
Before Release 9-30: C:\Program Files\Parker Hannifin\C3MGR2\DB
Release 9-30: C:\ProgramData\Parker Hannifin\C3MGR2_R09-30\DB\CHM
1. Right-click the CHM file and click Properties.
2. In the General tab of the Properties dialog box, click the Unblock button under Security at the bottom.
3. Click Apply and OK to save the settings.
For Windows 10, the file location is the ProgramData folder:
C:\ProgramData\Parker Hannifin\C3MGR2_R09-77\DB\CHM
The symptom is different in that the 'Navigation to the webpage was canceled' is not displayed and it is only blank, though the Contents / Index / Search is populated.
The fix is the same in that you click Unblock on the general tab of the properties of the file:
.