Erratic Invalid Viewstate issue in a .NET application

Question

I seem to be getting a \"invalid viewstate\" every now and then in the event viewer for my ASP.NET application.

Most of them (95%) seem to be referencing Scrip

Answer 1

Are you running a non-english Operation System?

For some reasons, the account name of "NT Authority\Network Service" has been localized in other languages.
Sadly, a lot of programs have the account name hard coded to the english name, and won't find the Network Service when running on foreign versions of Windows, leading to all kind of funky errors in the event log.

Answer 2

Viewstate issues are annoying and frustrating - I've noticed a few people have talked about having Viewstate issues in this thread. So, here are some suggestions you can look at in order.

1. I'd echo what Freddy Rios has said in the thread already. Make sure that you've hardcoded the machine key. This will solve the vast majority of these issues. The important thing about the ScriptResource link is that it should have a d parameter and a t parameter in the querystring. If it doesn't something else is wrong!

2. Don't let the user postback until your done. You could probably do this with javascript and a bit of css. From memory, I think there is a way to do this with a meta tag but it might be IE only.

3. I would look at is flushing the response early. I would think after the script manager would be best. But you might need to experiment a bit.

4. If your viewstate looks bloated, turn on GZip compression on in IIS.

5. If your viewstate has became really bloated and you can't get GZip compression turned on/or it has an undesired side affect. Then you can compress and uncompress the viewstate. http://www.codeproject.com/KB/viewstate/ViewStateCompression.aspx

6. If that still leaves you with a bloated viewstate, you could look at storing the viewstate locally. http://blog.arctus.co.uk/articles/2007/04/23/advanced-asp-net-storing-viewstate-in-a-database/ is a good starting point.

Answer 3

I guess you are using ASP.NET AJAX. I am having the same problem. Sporadically I would find this exception in my Event Log, and the requested path is ALWAYS ScriptResource.axd.

Using fixed validationKey and decryptionKey in machineKey did not fix the problem for me.

Based on what I was able to gather, I tend to believe that this error has nothing to do with the ViewState whatsoever; my theory is that for some reason, certain UAs somehow mess up the "d" parameter of the ScriptResource.axd. The problem is easily replicable by requesting the offending path manually. This gives an "Invalid ViewState" exception, even though ViewState doesn't even apply here.

Digging through my logs, I found for example:

This request is served OK (200): /ScriptResource.axd?d=oFCAB7_vUyp7Hhe9lxZBz37lpoAxhfbWwwdfFy3Zd3z41W_33Y_9Dq6i10g9Q1NRCY1n0_DNg1nE6-DDbsD6r4EiuwoeDzp9mjDDfBNLb1k1&t=41df03cc

This slightly different request is also served OK (200): /ScriptResource.axd?d=oFCAB7_vUyp7Hhe9lxZBz37lpoAxhfbWwwdfFy3Zd3z41W_33Y_9Dq6i10g9Q1NR5ijsxQts4AfbJdACRwmQ8sHt6UAzui3spEnooPneTz01&t=41df03cc

This request fails with a 500 response and the Invalid ViewState exception: /ScriptResource.axd?d=oFCAB7_vUyp7Hhe9lxZBz37lpoAxhfbWwwdfFy3Zd3z41W_3products$ctl00$AddToCart1$id

If you look closely, the first few characters on all three request are the same, but the last few characters of the last request (in bold) clearly is Control ID "products$ctl00$AddToCart1$id" (I have a controls named products and AddToCart). I don't know how this ID got there, but in my case this is what is causing all these Invalid ViewState exceptions.

I'm not sure whether this is the same case as the OP or not, but I notice Martin's Request URL ends in "html", which is a bit of a coincidence for a parameter that is supposed to be a key...

I already have a headache thanks to this problem. And so far, the most insightful post I came across is this one http://bytes.com/topic/asp-net/answers/861764-invalid-viewstate-system-string-decryptstringwithiv

Any insights?

Answer 4

I've seen problems like this when the Viewstate is too large. I've seen it happen becaue of the problem Freddy describes.

I generally dislike the idea of using Viewstate. Can you turn Viewstate off altogether?