Your Sisulizer 1.x, Sisulizer V2008, Sisulizer V2010 or Sisulizer V3 license keys will not work with Sisulizer Version 4 (Read what is new in Sisulizer Version 4).
We also highly recommend to use a download manager like FDM (Free Download Manager). A good download manager can resume stopped downloads and also downloads much faster. Our download routines are optimized for the usage of download managers.
Users with a valid license key can download older builds, e.g. Sisulizer V3, here. Please be aware that we can only support the newest build of Sisulizer.