System.Configuration.ConfigurationErrorsException: The value for the property 'tagType' is not valid. The error is: The string must be at least 1 characters long. () () ---> System.ArgumentException: The string must be at least 1 characters long.
  at System.Configuration.NullableStringValidator.Validate (System.Object value) [0x000ac] in /usr/src/tmp/mono/mcs/class/System.Web/System.Web.Configuration_2.0/NullableStringValidator.cs:85 
  at System.Configuration.ConfigurationProperty.Validate (System.Object value) [0x0000c] in /usr/src/tmp/mono/mcs/class/System.Configuration/System.Configuration/ConfigurationProperty.cs:172 
  at System.Configuration.ConfigurationElement.SetPropertyValue (System.Configuration.ConfigurationProperty prop, System.Object value, Boolean ignoreLocks) [0x00000] in /usr/src/tmp/mono/mcs/class/System.Configuration/System.Configuration/ConfigurationElement.cs:158 --- End of inner exception stack trace ---

  at System.Configuration.ConfigurationElement.SetPropertyValue (System.Configuration.ConfigurationProperty prop, System.Object value, Boolean ignoreLocks) [0x0000d] in /usr/src/tmp/mono/mcs/class/System.Configuration/System.Configuration/ConfigurationElement.cs:169 
  at System.Configuration.ConfigurationElement.set_Item (System.String property_name, System.Object value) [0x0002f] in /usr/src/tmp/mono/mcs/class/System.Configuration/System.Configuration/ConfigurationElement.cs:233 
  at System.Configuration.ConfigurationElement.set_Item (System.Configuration.ConfigurationProperty property, System.Object value) [0x00000] in /usr/src/tmp/mono/mcs/class/System.Configuration/System.Configuration/ConfigurationElement.cs:216 
  at System.Web.Configuration.TagMapInfo.set_TagType (System.String value) [0x00000] in /usr/src/tmp/mono/mcs/class/System.Web/System.Web.Configuration_2.0/TagMapInfo.cs:106 
  at System.Web.Configuration.TagMapInfo..ctor (System.String tagTypeName, System.String mappedTagTypeName) [0x00012] in /usr/src/tmp/mono/mcs/class/System.Web/System.Web.Configuration_2.0/TagMapInfo.cs:67 
  at System.Web.Configuration.TagMapCollection.CreateNewElement () [0x00000] in /usr/src/tmp/mono/mcs/class/System.Web/System.Web.Configuration_2.0/TagMapCollection.cs:65 
  at System.Configuration.ConfigurationElementCollection.CreateNewElementInternal (System.String elementName) [0x00006] in /usr/src/tmp/mono/mcs/class/System.Configuration/System.Configuration/ConfigurationElementCollection.cs:300 
  at System.Configuration.ConfigurationElementCollection.OnDeserializeUnrecognizedElement (System.String elementName, System.Xml.XmlReader reader) [0x0010e] in /usr/src/tmp/mono/mcs/class/System.Configuration/System.Configuration/ConfigurationElementCollection.cs:486 
  at System.Configuration.ConfigurationElement.DeserializeElement (System.Xml.XmlReader reader, Boolean serializeCollectionKey) [0x00264] in /usr/src/tmp/mono/mcs/class/System.Configuration/System.Configuration/ConfigurationElement.cs:343 
  at System.Configuration.ConfigurationElement.DeserializeElement (System.Xml.XmlReader reader, Boolean serializeCollectionKey) [0x002f0] in /usr/src/tmp/mono/mcs/class/System.Configuration/System.Configuration/ConfigurationElement.cs:356 
  at System.Configuration.ConfigurationSection.DeserializeSection (System.Xml.XmlReader reader) [0x00095] in /usr/src/tmp/mono/mcs/class/System.Configuration/System.Configuration/ConfigurationSection.cs:132 
  at System.Web.Configuration.PagesSection.DeserializeSection (System.Xml.XmlReader reader) [0x00000] in /usr/src/tmp/mono/mcs/class/System.Web/System.Web.Configuration_2.0/PagesSection.cs:269 
  at System.Configuration.Configuration.GetSectionInstance (System.Configuration.SectionInfo config, Boolean createDefaultInstance) [0x000ba] in /usr/src/tmp/mono/mcs/class/System.Configuration/System.Configuration/Configuration.cs:254 
  at System.Configuration.ConfigurationSectionCollection.get_Item (System.String name) [0x00034] in /usr/src/tmp/mono/mcs/class/System.Configuration/System.Configuration/ConfigurationSectionCollection.cs:67 
  at System.Configuration.Configuration.GetSection (System.String path) [0x0006c] in /usr/src/tmp/mono/mcs/class/System.Configuration/System.Configuration/Configuration.cs:216 
  at System.Web.Configuration.WebConfigurationManager.GetSection (System.String sectionName, System.String path) [0x00007] in /usr/src/tmp/mono/mcs/class/System.Web/System.Web.Configuration_2.0/WebConfigurationManager.cs:256 
  at System.Web.Configuration.WebConfigurationManager.GetSection (System.String sectionName) [0x00035] in /usr/src/tmp/mono/mcs/class/System.Web/System.Web.Configuration_2.0/WebConfigurationManager.cs:250 
  at System.Web.UI.TemplateParser.AddNamespaces (System.Collections.ArrayList imports) [0x00016] in /usr/src/tmp/mono/mcs/class/System.Web/System.Web.UI/TemplateParser.cs:144 
  at System.Web.UI.TemplateParser..ctor () [0x00023] in /usr/src/tmp/mono/mcs/class/System.Web/System.Web.UI/TemplateParser.cs:83 
  at System.Web.UI.BaseTemplateParser..ctor () [0x00000] in /usr/src/tmp/mono/mcs/class/System.Web/System.Web.UI/BaseTemplateParser.cs:35 
  at System.Web.UI.TemplateControlParser..ctor () [0x0000e] in /usr/src/tmp/mono/mcs/class/System.Web/System.Web.UI/TemplateControlParser.cs:56 
  at System.Web.UI.PageParser..ctor (System.String virtualPath, System.String inputFile, System.Web.HttpContext context) [0x00025] in /usr/src/tmp/mono/mcs/class/System.Web/System.Web.UI/PageParser.cs:76 
  at System.Web.UI.PageParser.GetCompiledPageInstance (System.String virtualPath, System.String inputFile, System.Web.HttpContext context) [0x00000] in /usr/src/tmp/mono/mcs/class/System.Web/System.Web.UI/PageParser.cs:100 
  at System.Web.UI.PageHandlerFactory.GetHandler (System.Web.HttpContext context, System.String requestType, System.String url, System.String path) [0x00000] in /usr/src/tmp/mono/mcs/class/System.Web/System.Web.UI/PageHandlerFactory.cs:40 
  at System.Web.HttpApplication.GetHandler (System.Web.HttpContext context) [0x00059] in /usr/src/tmp/mono/mcs/class/System.Web/System.Web/HttpApplication.cs:1124 
  at System.Web.HttpApplication+<>c__CompilerGenerated3.MoveNext () [0x006ad] in /usr/src/tmp/mono/mcs/class/System.Web/System.Web/HttpApplication.cs:895