Can UPX (upx.sourceforge.net) compact .net executables/dlls ?

upx: a.exe: CantPackException: .NET files (win32/net) are not yet supported

That is what the most recent version (3.04, 27 Sep 2009) tells me.

  • Just a follow up. I downloaded current version (UPX 3.07, September 08, 2010) and still getting this message. Nov 23 '10 at 18:44
  • Follow up - version 3.94 from 5/12/2017 still getting this message
    – DAG
    Apr 30 '18 at 20:10

UPX is only for native executables. There are a number of compressors for .NET executables around you could try my one RPX it does good compression even on small executables and can bundle multiple DLL(s) into a single .EXE file.

However there are some limitations caused by the manner, or more precisely the order, by which .NET looks for additional assemblies to load and where from (i.e 1. GAC, 2. File system, 3. Bundle) and is complicated more if you are using AppDomains inside your application.

Check the docs for more details. Hope that helps.

Please note: This is my project and as such this answer should not be seen as an endorsement from a third party. That said I do use it regularly, it is open source and it is my hope that others may benefit from it.

  • 1
    I see RPX as an alternative. It doesn't look like anything has happened with it in 4 years though. Is it done or did you stop working on it? Also Chrome doesn't like your codeplex project (although it appears safe). Mar 11 '16 at 14:56
  • I stopped updating that codeplex repo. It turned out a bunch of hackers were using it to distribute malware. Thats why that site has been flagged as containing malware and why some anti-virus software now detects any application packed with RPX as a virus. Its pretty frustraiting tbh.
    – Phill Tew
    Sep 8 '16 at 0:03
  • That would be really frustrating. :/ Sep 8 '16 at 3:28

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