Operation is not valid due to the current state of the object.

Operation is not valid due to the current
state of the object.

Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

Exception Details: System.InvalidOperationException: Operation is not valid due to the current state of the object.

Source Error:

An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.

Stack Trace:

[InvalidOperationException: Operation is not valid due to the current state of the object.]

System.Web.HttpValueCollection.ThrowIfMaxHttpCollectionKeysExceeded() +2692302

System.Web.HttpValueCollection.FillFromEncodedBytes(Byte[] bytes, Encoding encoding) +61

System.Web.HttpRequest.FillInFormCollection() +148

[HttpException (0x80004005): The URL-encoded form data is not valid.]

System.Web.HttpRequest.FillInFormCollection() +206

System.Web.HttpRequest.get_Form() +68

System.Web.HttpRequest.get_HasForm() +8735447

System.Web.UI.Page.GetCollectionBasedOnMethod(Boolean dontReturnNull) +97

System.Web.UI.Page.DeterminePostBackMode() +63

System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +133

Operation is not valid due to the current state of the
object.这种类型的错误有很多，很多都是针对linq的，但是如果是下面的错误类型System.Web.HttpValueCollection.ThrowIfMaxHttpCollectionKeysExceeded() +2692302

那就是因为

因为上年12月29号那次微软发布的最后一次非正常更新程序引起的．在这次安全更新中对于asp.net单次的提交量做了一个最大量限制1000，出现这个异常正是因为页面提交量超过了1000这个限制．这个可以在web.config中更改：

<appSettings>

<add key="aspnet:MaxHttpCollectionKeys" value="5000" />

</appSettings>