Another solution for server application unavailable

When we setProgramIf both. Net framework1.1 and. Net framework2.0 exist on the server, errors may occur,
English:
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.

Chinese:
The server application is unavailable.
The Web application you are attempting to access on this web server is currently unavailable. Please click "refresh" in the web browser to try your request again.

Administrator Note: you can find the error details for the specific request failure cause in the system event log of the Web server. Check this log item to find out the cause of this error.

One possible factor is that the connection pool used on the site is unclear, or the default value is 1.1, or the applications 2.0 and 1.1 share the application pool, the solution is to separate the 1.1 and 2.0 application pools, or create a separate application pool for your website, which is the safest way.