Re: Validation of viewstate MAC failed - only on windows CE device

I figured out what the issue was. In some environments (IE on a windows CE
device, in my case) hidden fields can only be a certain length. I don't
know what the length is, but in some of my pages I must have exceeded it. I
turned event validation off in the web config, and I made the page store the
viewstate in the session. Storing the viewstate in the session can cause a
wrinkle when using the back button -which I don't have a solution for yet,
but at least I'm not getting these errors.


"Teemu Keiski" <joteke@xxxxxxxxxxxxxxx> wrote in message
news:u4$SLxJkGHA.4508@xxxxxxxxxxxxxxxxxxxxxxx
Hi,

you might want to report this on:
http://forums.asp.net/thread/1173230.aspx


--
Teemu Keiski
ASP.NET MVP, AspInsider
Finland, EU
http://blogs.aspadvice.com/joteke



"Jeremy Chapman" <nospam@xxxxxxxxxx> wrote in message
news:eMWSTSDkGHA.1276@xxxxxxxxxxxxxxxxxxxxxxx
This is odd behavior. In my aspnet 2.0 app (basic app, nothing out of
the ordinary here), if I am using my iPAQ handheld device and I hit the
refresh button on my page, I get an error "Validation of viewstate MAC
failed. If this application is hosted by a Web Farm or cluster, ensure
that <machineKey> configuration specifies the same validationKey and
validation algorithm. AutoGenerate cannot be used in a cluster."

The interesting thing is I can not reproduce this using IE or Opera on my
desktop. The user agent reported by my iPAQ browser is "Mozilla/4.0
(compatible; MSIE 4.01; Windows CE; PPC; 240x320)"

I also tried adding the following machineKey to my macine.config file,
which didn't help:

<machineKey
validationKey="9CCEC30E6D1695636BC548918FC190EAC06714B6B44CCA2168B7DB439EC6684025E84514A8298545E74B015E22B69B1C3DD845F237BE470FC5650182F46B9111"
decryptionKey="126EA9F8AD6016492548AA59BAEB5D8012B947145126A19A"
validation="SHA1"/>

Any ideas?





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