Hi Everyone,
I have a very strange situation. We upgraded from MOSS to SP2010 (SP1) about a year ago and then recently changed to claims authentication and enabled Forms Based Authentication. Initially I thought everything was fine so don't know when this particular issue started but here it is:
My problem is that when I try to createany subsite I get a Security Validation for this Page is invalid. It also happens when I try to create new libraries. This only happens if I try to create a site using any of the built in SharePoint site templates. However, I saved one of my existing sites as a solution and if I use that as a basis for the new site, everything is fine.
Does anyone have any ideas as to what could be causing this?
Thanks!
LMP