无效的URI：无法确定URI的格式异常

Question

In my asp.net c# web application, I m unable to find where exactly in the code, this exception (Invalid URI: The format of the URI could not be determined.)is raised. The URL where the exception is coming is of format as below

http://somedomain.com/sepsisvte/sepsis.aspx?4040431page=2

If the problem is related to the structure of the URL then there are URL like below where I m not getting any exception at all

http://somedomain.com/sepsisvte/sepsis.aspx?4020894page=2 http://somedomain.com/sepsisvte/sepsis.aspx?4020894page=3

Its a quite large application and Its really difficult to find the origin of error. Any ideas?

The stacktrace is as below

[UriFormatException: Invalid URI: The format of the URI could not be determined.] System.Uri.CreateThis(String uri, Boolean dontEscape, UriKind uriKind) +5462488 System.Uri..ctor(String uriString) +20
umbraco.presentation.requestModule.rewrite404Url(String url, String querystring, Boolean returnQuery) +265
umbraco.presentation.requestModule.Application_BeginRequest(Object sender, EventArgs e) +237
System.Web.SyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +68 System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +75

Answer 1

That's because your url contains this "?404". Umbraco searches each url for this text, and if it exists, it rewrite the url. Check the source code here: https://searchcode.com/codesearch/view/28576630/ , search for this method: rewrite404Url.

One of the solutions is to try to prefix your query string key with underscore.