How do I fix invalid viewstate?

How do I fix invalid viewstate?

1. Introduction.
2. Verify that you are not running into issues that have been fixed.
3. Set the validationKey attribute if you are running in a Web farm.
4. Do not store dynamically generated types in view state in a Web farm.
5. Determine whether the problem is related to the view state MAC feature.

What does invalid viewstate mean?

Invalid viewstate can happen for a variety of reasons. Viewstate is too big and has not finished rendering before a user causes a postback on the page.

What causes invalid viewstate errors?

This error is usually caused by the asp worker process or the server recycling. By default, ASP.NET encrypts the viewstate using an Autogenerated Key when the process spins up. The problem comes when a client (browser) sends the request with a viewstate encrypted with the key generated by another worker process.

What is viewstate in IIS?

ViewState is a hidden field that is sent to the server with a postback (which normally uses post). It keeps the state of the controls when the page was rendered to the client, sending it with each postback.

How will you retrieve the value from ViewState?

If you need to store extraneous information in ViewState, you can get and set data in ViewState like you would any other key/value collection: //store value in viewstate ViewState[“someValue”] = “Foo”; //retrieve value from viewstate string someValue = ViewState[“someValue”]. ToString();

What is ViewState in JavaScript?

ViewState is a Server Side class object which though stores the data on Client Side but it is in Encrypted Form (Hashed format) and hence cannot be read by Plain JavaScript. Thus the ViewState variable is accessed inside JavaScript code with the help of Server Side Code Blocks in ASP.Net with C# and VB.Net.

How do you get ViewState?

You can simply access the hidden form element that holds the viewstate. The name of the control is __viewstate . var vCode = documents. forms[0][‘__VIEWSTATE’].

Which one of the following is incorrect about ViewState?

– If a ViewState of a certain control has to be disabled, then set EnableViewState=”false”. the information inside the viewstate is not encrypted, just encoded, so the 2nd option is false too.

Is ViewState secure?

The VIEWSTATE is a security risk if it is not encrypted (anyone could modify the VIEWSTATE values and POST to your pages.) If that page can decode the VIEWSTATE then it is not encrypted.

What is ViewState JavaScript?

What to do if validation of VIEWSTATE Mac failed?

Validation of viewstate MAC failed. If this application is hosted by a Web Farm or cluster, ensure that configuration specifies the same validationKey and validation algorithm. AutoGenerate cannot be used in a cluster.

What causes a VIEWSTATE error in ASP.NET?

We have been getting some questions regarding viewstate-related errors like “The viewstate is invalid for this page and might be corrupted”. This error is usually caused by the asp worker process or the server recycling. By default, ASP.NET encrypts the viewstate using an Autogenerated Key when the process spins up.

What’s the purpose of the validationkey in VIEWSTATE?

The validationKey is used to validate ViewState and ensure it hasn’t been tampered with, and generate unique application-specific session IDs for out-of-process session storage. You can run into problems if the key changes between postbacks. A good article how to do this here, here, here and here.

What happens when the _ _ VIEWSTATE field is consumed?

When the __VIEWSTATE field is consumed, the server checks the current Page’s ViewStateUserKey property and validates it against the value that was used to generate the __VIEWSTATE field. If the values do not match, the request is rejected as potentially malicious.