R11 unusual Page Async Postback in error log

[AbleMods]

Recently we started noticing a new error in a clients error log "The page is performing an async postback but the ScriptManager.SupportsPartialRendering property is set to false." Here's the complete exception:

An error has occured at https://<domain>/Basket.aspx
Exception: Exception of type 'System.Web.HttpUnhandledException' was thrown. Stack Trace: at System.Web.UI.Page.HandleError(Exception e) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) at System.Web.UI.Page.ProcessRequest() at System.Web.UI.Page.ProcessRequest(HttpContext context) at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) Inner Exception: The page is performing an async postback but the ScriptManager.SupportsPartialRendering property is set to false. Ensure that the property is set to true during an async postback. Inner Exception Stack Trace: at System.Web.UI.ScriptManager.OnPageInitComplete(Object sender, EventArgs e) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

I did some digging and found references to a situation where the browser User Agent string could exceed the default 64 character limit in .Net. Specifically iPads have a pretty long user agent string. When the .Net default limit of 64 characters is exceeded, this error can be thrown.

We have heavily customized the basket page. And it's only the basket page where we are seeing this error. So most likely a customization of ours has created this scenario. But I wanted to let the Able folks know about it just in case.

My solution was to edit the web.config and add this line to the <system.web> section:

Code: Select all

<browserCaps userAgentCacheKeyLength="256" />

I'll post back in a few days whether this eliminates the error.

[rlopez]

Over the last week we have starting seeing slower than normal load page times when first opening a browser. We checked both IE and firefox and condition is the same. Our site does not contain a large amount of customization. Did not see this error above in the basket but did see it in the product. Have not updated web.config file yet. However the error points to a Async problem. Here is the error.

Severity: Error
Message: An error has occured at https://Domain/product.aspx
Exception: Exception of type 'System.Web.HttpUnhandledException' was thrown.
Stack Trace: at System.Web.UI.Page.HandleError(Exception e) at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)
at System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) at System.Web.UI.Page.ProcessRequest() at System.Web.UI.Page.ProcessRequest(HttpContext context) at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()
at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

[mazhar]

Is it still happening? Error details doesn't seem much helpful. I wonder if there are more details in App_Data/logs/app.log file.

[AbleMods]

No, not a single error since I increased the browserCaps value to 256. Either something with a bad/incorrect user agent string was hitting the site, or the browserCaps change resolved the issue.

I checked app.log, nothing more there than what was in the error log.

Sure wish I knew why it's not happening any more - don't like it when I cannot tell if something is really fixed...