Today I encountered an exception while working on an application. The exception was “configuration system failed to initialize”. The problem I was having in my application configuration file was that I declared the <appSettings> tag immediately after the root tag <configuration>.
The schema of a configuration file requires that the <configSections> tag is the first child of the root tag. Thus, if you use any other tag as the first child of the root <configuration> tag, the application would throw an exception. So the <configSections> tag should always immediately follow the root <configuration> tag.
Correct Format
<?xml version="1.0"?>
<configuration>
<configSections>
<sectionGroup name="applicationSettings" type="System.Configuration.ApplicationSettingsGroup,
System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" >
<section name="your_project_name.Properties.Settings" type="System.Configuration.ClientSettingsSection, System, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
</sectionGroup>
Wrong Format
<?xml version="1.0"?>
<configuration>
<appSettings>
...
...
...
</appSettings>
<configSections>
.....
</configSections>
This is just one of the reasons for which the exception is thrown. There is more than one reason for it. For me, this solution worked. I hope it works for you as well!
I hope this helps!