Server application unavailable error !!

The "server application unavailable" error occurred recently during project deployment! After you re-create the virtual directory, you can do it, but it didn't take long before the error occurred! I found the information to know that it was an application in IE 6. Program Isolation mechanism. The default application isolation mechanism of IIS is called: "Working Process Isolation Mode" In this mode, applications are divided into multiple groups, each group is an "Application pool", and each application pool is isolated from each other.
The cause of the above error is :.. NET Framework 2.0 program and. net framework1.1 (or 1.0) programs are put into the same application pool (ultapppool pool by default), that is, managed by the same worker process: w3wp.exe, however, a single working process cannot manage different programs (or different versions of programs) at the same time. If you first access the. NET Framework 1.1 page, the working process first loads and manages the 1.1 version of the Assembly, and then accesses the. NET Framework 2.0 web application page, Server The application unavailable error is returned. Conversely, If w3wp.exe in the development application pool has accessed the 2.0 web application before it is started (the application assembly has been loaded. net Framework 1.1 web assembly). When you access the Web application page of 1.0 or, a Chinese prompt such as "server application unavailable" will also appear. (You can use w3wp.exe to test .)
solution: Create an application pool in IIS and select your application pool. net framework2.0 virtual directory, click "properties"-> select the application pool you just created in "application pool", and click "OK ".