Net framework interference of versions

Question

1.00/5 (1 vote)

See more:

.NET3.5

.NET4.5

we implemented a win form app with net framework 4.5.1 running in systems that runs a web app using net framework 3.5, when we install the 4.5.1 version, some of web app parts doesn't work correctly in some of windows(all the windows versions is 7), is there any way to have 4.5.1 in portable mode or another way else?

What I have tried:

we installed win 7 service pack 1 and did not solve the problem

Posted 22-Jun-21 18:09pm

Member 11151914

Updated 22-Jun-21 22:04pm

Add a Solution

Comments

Maciej Los 23-Jun-21 3:40am

I'd suggest to use the same version as web app. See: How to downgrade .net application framework version in visual studio?[^]

2 solutions

Add a Solution

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Richard Deeming · Answer 1 · 2021-06-22T21:48:00

Solution 1

.NET Framework 3.5 and .NET Framework 4.x install side-by-side. Installing one will not alter the behaviour of applications written for the other.

If it's breaking a web application, then you need to double-check that the CLR version selected for the App Pool has not been changed.

Beyond that, we can't help you, since you haven't provided any details of the failing code nor the error(s).

Posted 22-Jun-21 21:48pm

Richard Deeming

Comments

Maciej Los 23-Jun-21 4:04am

5ed!

Member 11151914 23-Jun-21 9:10am

We don't see any errors,the problem is when you want to open some parts of website,it doesn't have any reactions till the 4.5 framework be removed

Richard Deeming 23-Jun-21 9:25am

Nobody can guess what you mean by "doesn't have any reactions".

Member 11151914 24-Jun-21 10:00am

the website do nothing when we want to open some parts of it and we don't see any errors from that

Richard Deeming 24-Jun-21 10:08am

Oh, well, that's clear then. There's a missing comma on line 42 of SecretCode.aspx.cs which causes it to break. 🤦‍♂️

Seriously, how do you think anyone is going to be able to help you fix an error that we cannot see in code which we do not have access to?

Hundreds of thousands of people have successfully run .NET 3.x applications on servers with .NET 4.x installed. It's not a problem with the framework; it's a problem with your code.

Maciej Los · Answer 2 · 2021-06-22T22:04:00

In addition to Richard's answer, there's a list of articles which states about backward compatibility and possible configurations:
How to: Configure an app to support .NET Framework 4 or later versions | Microsoft Docs[^]
Migration of .Net 2.0/3.0/3.5 Application to .Net 4.5[^]
All about | ASP.NET Blog[^]
How to set an IIS Application or AppPool to use ASP.NET 3.5 rather than 2.0 - Scott Hanselman's Blog[^]

Net framework interference of versions

2 solutions

Solution 1

Solution 2

Add your solution here

Preview 0

Net framework interference of versions

2 solutions

Solution 1

Solution 2

Add your solution here

Preview 0

Existing Members

...or Join us