"Unrecognized configuration section connectionStrings."

Question

I had been working on a project in VS2005 that utilized a local connection to an Access DB.

In the past week, I installed .NET framework 3.5 for use w/ a different project as well as VS6.

I went back to my VS2005 application and suddenly there are big issues:

In the designer for any class utilizing my OLEDB connection showed this:

Unable to cast object of type 'System.Configuration.DefaultSection' to type 'System.Configuration.ConnectionStringsSection'. Hide

at System.Configuration.Configuration.get_ConnectionStrings() at Microsoft.VisualStudio.Shell.Design.Serialization.ConfigurationHelperService.ReadConnectionStrings(String configFileName, DocData configDocData, String prefix) at Microsoft.VisualStudio.Editors.SettingsDesigner.AppConfigSerializer.Deserialize(DesignTimeSettings Settings, String SectionName, DocData AppConfigDocData, MergeValueMode mergeMode, IUIService UIService) at Microsoft.VisualStudio.Editors.SettingsGlobalObjects.SettingsFileGlobalObject.LoadSettings(String fileName) at Microsoft.VisualStudio.Editors.SettingsGlobalObjects.SettingsFileGlobalObject.BuildType() at Microsoft.VisualStudio.Editors.SettingsGlobalObjects.SettingsFileGlobalObject.GetObjectType() at Microsoft.VisualStudio.Shell.Design.GlobalType.get_ObjectType() at Microsoft.VisualStudio.Shell.Design.GlobalObject.GetHashCode() at Microsoft.VisualStudio.Shell.Design.GlobalObjectService.GlobalKey.GetHashCode() at System.Collections.Generic.ObjectEqualityComparer1.GetHashCode(T obj) at System.Collections.Generic.Dictionary2.FindEntry(TKey key) at Microsoft.VisualStudio.Shell.Design.GlobalObjectService.GetGlobalObjects(Type baseType) at Microsoft.VisualStudio.Shell.Design.GlobalObjectService.GetGlobalObjects() at Microsoft.VisualStudio.Design.Serialization.CodeDom.AggregateTypeResolutionService.GetTypeFromGlobalObjects(String name, Boolean throwOnError, Boolean ignoreCase) at Microsoft.VisualStudio.Design.Serialization.CodeDom.AggregateTypeResolutionService.GetType(String name, Boolean throwOnError, Boolean ignoreCase) at Microsoft.VisualStudio.Design.Serialization.CodeDom.AggregateTypeResolutionService.GetType(String name, Boolean throwOnError) at System.ComponentModel.Design.Serialization.CodeDomSerializerBase.GetType(ITypeResolutionService trs, String name, Dictionary2 names) at System.ComponentModel.Design.Serialization.CodeDomSerializerBase.FillStatementTable(IDesignerSerializationManager manager, IDictionary table, Dictionary2 names, CodeStatementCollection statements, String className) at System.ComponentModel.Design.Serialization.TypeCodeDomSerializer.Deserialize(IDesignerSerializationManager manager, CodeTypeDeclaration declaration) at System.ComponentModel.Design.Serialization.CodeDomDesignerLoader.PerformLoad(IDesignerSerializationManager manager) at Microsoft.VisualStudio.Design.Serialization.CodeDom.VSCodeDomDesignerLoader.PerformLoad(IDesignerSerializationManager serializationManager) at Microsoft.VisualStudio.Design.Serialization.CodeDom.VSCodeDomDesignerLoader.DeferredLoadHandler.Microsoft.VisualStudio.TextManager.Interop.IVsTextBufferDataEvents.OnLoadCompleted(Int32 fReload)

And when I ran the app, I encounter the following exception on startup:

"Unrecognized configuration section connectionStrings."

In looking online, these issues seem to commonly relate to things built in VS2005 and deployed on .net 1.1 framework; but this is all running as a windows forms application locally within VS (not on IIS). I've tried uninstalling and reinstalling VS2K5 to no avail.

Any thoughts? Thanks, Matt

Vin.X Vin.X · Accepted Answer · 2013-08-28T12:20:20

This is a really old post, i know, but i have had the same problem recently, i have fixed it by putting:

 <configSections>
    <section name="appSettings" type="System.Configuration.AppSettingsSection, System.Configuration, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" restartOnExternalChanges="false" requirePermission="false"/>
    <section name="connectionStrings" type="System.Configuration.ConnectionStringsSection, System.Configuration, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" requirePermission="false"/>
 <configSections>

before my connection strings:

    <connectionStrings>
        <add name="XXX" connectionString="Data Source=.;Initial Catalog=db;User Id=user;Password=pw;" providerName="System.Data.SqlClient"/>
      </connectionStrings>

so my app.config looks like:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
     <configSections>
        <section name="appSettings" type="System.Configuration.AppSettingsSection, System.Configuration, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" restartOnExternalChanges="false" requirePermission="false"/>
        <section name="connectionStrings" type="System.Configuration.ConnectionStringsSection, System.Configuration, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" requirePermission="false"/>
     <configSections>   
    <connectionStrings>
        <add name="XXX" connectionString="Data Source=.;Initial Catalog=db;User Id=user;Password=pw;" providerName="System.Data.SqlClient"/>
      </connectionStrings>
</configuration>

In C# I am using below code to retrieve my connection string:

ConfigurationFileMap fileMap = new ConfigurationFileMap("myApp.config"); //Path to your config file
Configuration configuration = ConfigurationManager.OpenMappedMachineConfiguration(fileMap);
this.connectionString = configuration.ConnectionStrings.ConnectionStrings["XXX"].ConnectionString;

"Unrecognized configuration section connectionStrings."

4 Answers