Input string was not in a correct format.
at System.Number.StringToNumber(String str, NumberStyles options, NumberBuffer& number, NumberFormatInfo info, Boolean parseDecimal)
at System.Number.ParseInt32(String s, NumberStyles style, NumberFormatInfo info)
at System.String.System.IConvertible.ToInt32(IFormatProvider provider)
at System.Convert.ToInt32(Object value)
at NVelocity.Runtime.Parser.Node.MathUtil.Sub(Type maxType, Object left, Object right)
at NVelocity.Runtime.Parser.Node.ASTSubtractNode.Value(IInternalContextAdapter context)
at NVelocity.Runtime.Parser.Node.ASTSetDirective.Render(IInternalContextAdapter context, TextWriter writer)
at NVelocity.Runtime.Parser.Node.ASTBlock.Render(IInternalContextAdapter context, TextWriter writer)
at NVelocity.Runtime.Parser.Node.ASTIfStatement.Render(IInternalContextAdapter context, TextWriter writer)
at NVelocity.Runtime.Parser.Node.ASTBlock.Render(IInternalContextAdapter context, TextWriter writer)
at NVelocity.Runtime.Directive.Foreach.Render(IInternalContextAdapter context, TextWriter writer, INode node)
at NVelocity.Runtime.Parser.Node.ASTDirective.Render(IInternalContextAdapter context, TextWriter writer)
at NVelocity.Runtime.Parser.Node.SimpleNode.Render(IInternalContextAdapter context, TextWriter writer)
at NVelocity.Template.Merge(IContext context, TextWriter writer)
at Netism.SatelliteExtreme.TemplateEngine.Render(String TemplatePath, String TemplateName, PortalModuleBase module, Page page, String datasource, String Query)