IDL 8.6/ENVI 5.4 help not launching on MacOS 10.12.5

Description:

A recent update to Mac OS has been released. If you installed this latest update, then if you try to launch the ENVI and IDL help, it will fail. If you try to launch the help by typing "?" into command-line IDL, then the following error will occur:
IDL> 0:86: execution error: "file:///Applications/harris/envi54/idl86/help/online_help/help_CSH.htm" doesn't understand the open location

Solution:

Harris has a bug report about this issue in its system (IDL-69794). Hopefully, this issue will be fixed in a future version of IDL. A couple of possible workarounds are:

1) Open a browser, and paste the following address:
file:///Applications/harris/envi54/idl86/help/online_help/help_CSH.htm
2) Use the help system available on the Harris website:
 https://www.harrisgeospatial.com/docs/home.html

(Written by DS 6/1/2017, Reviewed by JU 6/9/2017)