Symptoms
After you install the August Preview of Quality Rollup or September 11, 2018, .NET Framework update, instantiation of SqlConnection can throw an exception.
Use of a SqlConnection constructor can lead to a stack trace that resembles the following:
System.Runtime.Serialization.SerializationException at System.AppDomain.get_Evidence() at System.AppDomain.get_Evidence() at System.Configuration.ClientConfigPaths.GetEvidenceInfo(AppDomain appDomain, String exePath, String& typeName) at System.Configuration.ClientConfigPaths.GetTypeAndHashSuffix(AppDomain appDomain, String exePath) at System.Configuration.ClientConfigPaths..ctor(String exePath, Boolean includeUserConfig) at System.Configuration.ClientConfigPaths.GetPaths(String exePath, Boolean includeUserConfig) at System.Configuration.ClientConfigurationHost.RequireCompleteInit(IInternalConfigRecord record) at System.Configuration.BaseConfigurationRecord.GetSectionRecursive(String configKey, Boolean getLkg, Boolean checkPermission, Boolean getRuntimeObject, Boolean requestIsHere, Object& result, Object& resultRuntimeObject) at System.Configuration.BaseConfigurationRecord.GetSection(String configKey) at System.Configuration.ConfigurationManager.GetSection(String sectionName) at System.Data.SqlClient.SqlConnection..cctor()
Workaround
Workaround 1
Add the following lines in the configSection of the App.Config file of the application:
<section name="SqlColumnEncryptionEnclaveProviders" type="System.Data.SqlClient.SqlColumnEncryptionEnclaveProviderConfigurationSection, System.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" />
Note If your application doesn't include an app.config file, we recommend that you create and deploy an app.config file that contains this information in the configSection.
If Workaround 1 doesn't work, try Workaround 2.
Workaround 2
Identify a place in the app domain that runs before any objects have been added to the logical call context. Add code to force ConfigurationManager to try to load a section that doesn't exist in any configuration files. For example:
System.Configuration.ConfigurationManager.GetSection("SectionNameThatDoesNotExistInAnyConfigurationFile");
For more information about this issue see the GitHub article Mitigation: Deserialization of objects across app domains.
Status
Microsoft is researching this issue and will provide an update in an upcoming release.
