"The input is not a valid Base-64 string..."

Sep 20, 2012 at 11:09 AM
Edited Sep 20, 2012 at 11:09 AM

Hi guys, I keep getting this exception on my website running BlogEngine. Here is the stack trace:


System.Web.HttpException (0x80004005): The state information is invalid for this page and might be corrupted. ---> System.Web.UI.ViewStateException: Invalid viewstate.
at System.Convert.FromBase64String(String s)
at System.Web.UI.ObjectStateFormatter.Deserialize(String inputString)
at System.Web.UI.ObjectStateFormatter.System.Web.UI.IStateFormatter.Deserialize(String serializedState)
at System.Web.UI.Util.DeserializeWithAssert(IStateFormatter formatter, String serializedState) at System.Web.UI.HiddenFieldPageStatePersister.Load() --- End of inner exception stack trace ----


I keep getting this error along with Invalid Viewstate! Is this just someone sending malicious requests to my website? As far as I know there is no way to post-back the Post.aspx page, so how can this happen?



Sep 23, 2012 at 12:33 PM


Sep 26, 2012 at 1:39 PM

I analyzed the issue a bit further and as I suspected, it is a bot. No need to worry, just ban their IP address if possible.