STW help files are delivered in CHM (Compiled Help Module) format. This format is a standard created by Microsoft for Windows Help files containing images and documentation as hyperlinked documents, similar to webpages. Because the dynamic, hyperlinked nature of CHM files, they can pose a security risk when opened from an untrusted source. For this reason, recent versions of Windows can cause some problems when opening STW help files for the first time.

The image below shows what the error looks like:

There are two main causes of this issue:

  1. Downloaded form the internet, or email
  2. Opening from a network drive

Issue 1. is resolved by "Unblocking" the downloaded file. This is done in the properties dialog of hte file, available by right-clicking on the file in windows explorer and selecting properties. See the image below:

Issue 2. is resolved by copying the CHM file onto a local drive before opening (i.e., somewhere on the C: drive). It is not possible to open CHM files from a shared network resource. If the file must absolutely be shared on the network and only on the network, then as a workaround, it should be stored in zip file. This allows the file to opened without copying, but does require the additional step of opening the zip file and then opening the CHM file.