ASP.NET Viewstate error - Validation of viewstate MAC failed

re: ASP.NET Viewstate error - Validation of viewstate MAC failed

Jesse — Tue, 18 Mar 2008 19:39:31 GMT

Aha! I think that's exactly the problem I'm having with a produciton web application I maintain. Thanks so much.

re: ASP.NET Viewstate error - Validation of viewstate MAC failed

Joshua — Wed, 19 Mar 2008 09:49:18 GMT

Just thought that I'd point out, that while writing my own blogging software (which, sadly is offline, due to a memory leak (I think) that would take down the server every 12 hours or so - haven't had time to look into it yet) I encountered this a lot with comment spamming bots. They try and post to the page directly with what they pulled earlier, which included a viewstate.

Of course, trying later caused the viewstate to be invalid. It got so bad, that after I implemented an email function into the global.asax file for handling and reporting errors did I notice that it was averaging about 500+ a day. And my blog was by no means popular.

On the flip side, it was interesting to see the bots that could load the page, grab a valid viewstate, and manage a successful post (which I was developing anti spam/keyword filtering on). On those, I averaged about 2 to 3 a day.

re: ASP.NET Viewstate error - Validation of viewstate MAC failed

Tess — Wed, 19 Mar 2008 10:12:57 GMT

very interesting...

I think in your case though you are probably running into this which is very similar (in fact same error message) but different cause...

http://blogs.msdn.com/tess/archive/2007/06/11/a-case-of-invalid-viewstate.aspx

I know what you're saying about the spammers, I easily also get around 500 a day which is a bit sad because I have had to turn on comment moderation for a while to avoid getting publishing the spam comments since most of the time they are highly offensive. Lately they have also tried sending captcha text which is a bit ironic given that the blog doesnt use captcha but I guess they send out the same to all

Community server seems to catch most of the spam comments though these days, so I am leaning more and more towards turning off comment moderation...

ASP .NET ViewState Validation Errors

David Grey's Blog — Sun, 23 Mar 2008 00:52:28 GMT

Tess's If broken it is, fix it you should blog is always good for a read. Tess is an escalation engineer

re: ASP.NET Viewstate error - Validation of viewstate MAC failed

Craig — Mon, 13 Oct 2008 17:46:11 GMT

I saw the same problem on an aspx page with a gridview. All it was was a web tracker js file, at the bottom of the page, that was not getting downloaded. I commented out the tracker and all was well.

I can't decide if that's a bug in IE, the Framework, or the whole concept of ASP.Net!

re: ASP.NET Viewstate error - Validation of viewstate MAC failed

mike — Mon, 12 Jan 2009 21:19:25 GMT

Validation of viewstate MAC failed

Update: In my case I was NOT using gridview nor DataKeyNames nor slow loading page.

Small page with on two buttons, two text boxex, and dropdownlist. Clicking the button1 (add) caused the above error every time.

Problem turned out to be the form action property was pointing to a non-existent page! I used a code-behind method when the Add button is clicked and do not use form.submit. When I cleared the action property of the form, problem went away.

My "guess" is that the form submit happens before

the code-behind code is processed, since even in debug I would get the error before the breakpoint was hit.

Hope this leads to the final answer to this.

thanks!

Mike.

re: ASP.NET Viewstate error - Validation of viewstate MAC failed

Dave — Thu, 05 Mar 2009 17:52:10 GMT

this worked for me.

re: ASP.NET Viewstate error - Validation of viewstate MAC failed

Shane — Thu, 12 Mar 2009 00:55:36 GMT

Mike, you saved me!

I had tried every solution I could find for this problem, it turns out just the action property of my form tag was wrong. Thank you very much!

re: ASP.NET Viewstate error - Validation of viewstate MAC failed

GSingh — Mon, 13 Jul 2009 13:46:27 GMT

Hey...

i do all the things you

mention in your post and disable the view and event state at application level in web.config, but still getting the same error but at a very low rate then previous one. Do smhtin ;)