I made a sample test control with a button and a label
public partial class CMSInlineControls_test : CMS.ExtendedControls.InlineUserControl
{
public string test="";
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
Cache["test"] = "test";
}
else
{
test= ((string)Cache["test"]);
}
Label1.Text = test;
}
protected void Button1_Click(object sender, EventArgs e)
{
}
}
This works on my machine but accessing the site from elsewhere this error happens.
I also tried adding:
<pages validateRequest="false" enableEventValidation="false" viewStateEncryptionMode ="Never">
but did not fix the issue.