Hi Novac. If it is useful, I've just completed a download check and MD5 hash comparison using my links listed via the GWX website. All matched and assuming users downloads are not interrupted, the resultant downloads are still good.
A fresh installation of SH3 patched to 1.4b and a fresh download of GWX 3.0 installed over it, should cure your blues, assuming it is one or more files missing on your current installation.
@danlisa. Long time no see! I'm doin' great and I hope all is well with you and your family. How old is your daughter now?