# Error "must install .NET 3.5" on startup of FinalBuilder

**URL:** https://www.finalbuilder.com/forums/t/error-must-install-net-3-5-on-startup-of-finalbuilder/721
**Category:** Discussion
**Created:** [January 21, 2008, 10:33am UTC](https://www.finalbuilder.com/forums/t/error-must-install-net-3-5-on-startup-of-finalbuilder/721 "2008-01-21T10:33:07Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![hannes1234](https://www.finalbuilder.com/forums/letter_avatar_proxy/v4/letter/h/a5b964/32.png) [@hannes1234](https://www.finalbuilder.com/forums/u/hannes1234)
#### Post date: [January 21, 2008, 10:33am UTC](https://www.finalbuilder.com/forums/t/error-must-install-net-3-5-on-startup-of-finalbuilder/721/1 "2008-01-21T10:33:07Z")

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Hello,

when starting FinalBuilder 5, I get the error message

**"To run this application, you first must install one of the following versions of the .NET Framework: v3.5"**

But I am sure that I have installed the .NET Runtime 3.5. I even re-installed the .NET runtime 3.5

But still I get this error.

I am working on a .NET 3.5 Application which I want to build with final builder 5.

Thanks for hints,

Hannes

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### Author: ![hannes1234](https://www.finalbuilder.com/forums/letter_avatar_proxy/v4/letter/h/a5b964/32.png) [@hannes1234](https://www.finalbuilder.com/forums/u/hannes1234)
#### Post date: [January 21, 2008, 10:47am UTC](https://www.finalbuilder.com/forums/t/error-must-install-net-3-5-on-startup-of-finalbuilder/721/2 "2008-01-21T10:47:59Z")

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I have seen that Jeffery has the same problem on this thread:   
  
 [https://www.finalbuilder.com/forums.aspx?forumid=1&postid=5677&view=topic](https://www.finalbuilder.com/forums.aspx?forumid=1&postid=5677&view=topic)   
  
 So I also will switch over to this thread.   
  
 Hannes