ASP. NET "server application unavailable" error solution (Application Service unavailable)

ASP. NET "server application unavailable" error Solution
Server application unavailable
The Web application you are attempting to access on this web server is currently unavailable. Please hit the "refresh" button in your web browser to retry your request.

Administrator Note: an error message detailing the cause of this specific request failure can be found in the application event log of the Web server. please review this log entry to discover what caused this error to occur.

Then I asked for help. After carefully reading the IIS Help documentation, I found that this error was originally caused by the IIS6 application.ProgramIsolation mechanism. The default application isolation mechanism of IIS is called "Working Process Isolation Mode". In this mode, an application is divided into multiple groups, each of which is an "Application pool ", each application pool is isolated from each other. The benefits of isolation are security, stability, and so on. Each application pool in IIS is managed by a "worker process", that is, "w3wp.exe ". If you run multiple applications in the application pool, we can see multiple w3wp.exe. The created virtual directories are directed to the "defaultapppool" Worker Process of iis6.

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. net Framework 1.1 page, the worker first loads and manages the assembly of Version 1.1. net Framework 2.0 web application page, the server application unavailable error is returned. In contrast, 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 at this time. 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 .)

My friend didn't see this error on his development machine because he was developing based on. net Framework 2.0 project, always only access this 2.0 web program, and this has never accessed other web programs. There are already 1.0 projects on a friend's server, and they have been used all the time. This error has never been encountered before. In fact, most people only access the project being developed when developing a project. It is very likely that this problem has been ignored, but an error occurred during the release, making it messy.

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 ".

If your computer is mainly used to learn, develop, and test web programs, you can create an application pool similar to "dotnet2.0, all new 2.0 virtual directories will point to this application pool.