Blank CHM help files
I fell upon this issue today and wanted to post how to fix it in case there are others having the same issue.
If you come across a help file (CHM) that when you open it, it is blank there is an easy fix.
Go to where the CHM file is, right click on it and choose Properties. On the General tab in the bottom right, there will be a check box (or a button depending on the version of your Windows OS) that says Unblock. Check (or press) that and then press OK.
You will now be able to open the CHM file and see the contents.
