Could not load file or assembly ':This assembly is built by a runtime newer than the currently loaded runtime and cannot be loaded

Question

I Hvea 3 projects in my solution: BL, DL and the UI. All three projectshave a target framework of >NET 4; I have double-checked this by looking at the property page for each project. I am receiving the following error message when I try run the website at the hosting environment but not when I run it locally.

Could not load file or assembly 'BL' or one of its dependencies. This assembly is built by a runtime newer than the currently loaded runtime and cannot be loaded.

Thanks in advance!

Answer 1

-Go to IIS. -Default WebSite-> Your application Directory->Advance Settings->Application Pool-> Set your Version (Ex. ASP.NET v4.0) -Refresh your Application Directory and Browse it. It's done.

Answer 2

You have to update your webservice extension to allow framework 4.0 in IIS. To enable the Web service extension for ASP.NET 4.0:

1. Click Start, click Control Panel, click System Security, click Administrative Tools, and then click Internet Information Services (IIS) Manager.
2. If you need to connect to a remote IIS Server, right click the Internet Information Services node and click the Connect... option.
3. Type in the computer name for the remote IIS Server and credentials if necessary.
4. Click the Web Service Extensions folder. The security lockdown console appears in the frame on the right.
5. In the Web Service Extensions window, right-click the ASP.NET v4.X.XXXX, and then click Allow.