You are using really old and deprecated software (10 years old without any update for newest NSIS and newest Windows 7/8/10). There will be probably no answer for you issue as the project was stopped.
Please try Visual & Installer
) - NSIS extension for Microsoft Visual Studio 2005 - 2017
or RAD & Installer
) - NSIS expert for Embarcadero RAD Studio (Delphi/C++ Builder) 2009 - 10.2 Tokyo.
These tools have latest NSIS syntax so the freezing is not occurring. Creating NSIS scripts with them is much easier, they offer many modern features like syntax highlighting, code completion and many more that helps to write your script and they are always up-to-date.
If you have any problems feel free to ask here or contact me (I am developer).