Regex to parse package name and version number from nuget package filenames

I modified your expression slightly to:

^(.*?)\.((?:\.?[0-9]+){3,}(?:[-a-z]+)?)\.nupkg$

The main points are that I moved the . in front of the digits in the first non capturing group, and that I added an optional non capturing group for -alpha in the fourth string.

Replace with:

Package: \1 Version: \2

Test the regex live here.