How to Troubleshoot Response Buffer Limit Exceeded Error in Classic ASP

How do you troubleshoot a classic ASP website when it crashes with the following error message?

Response object error 'ASP 0251 : 80004005'
 
Response Buffer Limit Exceeded
 
/itnota/test.asp, line 0
 
Execution of the ASP page caused the Response Buffer to exceed its configured limit.

Turn Off Page Buffering

By default, page buffering in ASP is set to On so one way to do it is just to turn off the page buffering.

At the top of your ASP page, add the following line after the VBScript declaration (Line 2 – highlighted):

<% @Language="VBScript" %>
<% Response.Buffer = False %>

In general though, you do want to pose a limit so your data stream does not clog up your resources especially if you’re sharing the web server with other applications. That’s why the next solution would be a better one especially for production environment.

Modify Response Buffering Limit in IIS

Another way to solve this issue is explained below, demonstrated using IIS 10 but should work the same way with IIS 7 or later as well. This would be the best solution but you need access to your IIS.

1. Launch your IIS Manager and select your site on the Connections box on the left. Then double-click on the ASP on the right pane, which is under IIS section.

   

2. Once the ASP window is opened, look for Limit Properties and expand on it and go to Response Buffering Limit.

   If the value was never modified, you would see 4194304 which translates to roughly 4 MB.

   

3. This is the value, we want to modify so go ahead and change it to a larger number. In this example, we put in 64000000 (~64 MB, not quite but you get the point), basically adjust according to your need.

   

4. Once you entered the value, just click on the Apply link button to save all settings.

The effect should be immediate without requiring a restart of IIS or Application Pool. That’s all there is to it.

Further Reading

IIS 6.0: “Response buffer limit exceeded”
Response Buffer Limit Exceeded