Operations that change non-concurrent collections must have exclusive access. A concurrent update was performed on this collection and corrupted its state. The collection's state is no longer correct. @template_scope(_include_footer) ################################ at System.Collections.Generic.Dictionary`2.FindValue(TKey key) at siteface.Core.Template.Execute(String html) in /home/simon/Documents/siteface/siteface/sitefaceCore/Core/Template.cs:line 631 at siteface.Core.Template.Execute() in /home/simon/Documents/siteface/siteface/sitefaceCore/Core/Template.cs:line 604 at TemplateSlang.TplCall.Visit(ExecContext e) in /home/simon/Documents/siteface/siteface/sitefaceCore/TemplateSlang/TemplateSlangMain.cs:line 3441