Dotfuscator : Error after obfuscation

I am using dotfuscator to obfuscate my vb.net application. But i am getting error while running the obfuscated file.

Below is the error when i open the exe which is obfuscated.

"The settings property 'Import' was not found. ImportSetting"

My application uses .exe.config file which has setting like below

<userSettings><myapp.My.MySettings><setting name="Import" serializeAs="String"><value>True</value></setting></myapp.My.MySettings></userSettings>

If i don't obfuscate then application works fine. The error comes only if i obfuscate the my application.

Procedure i follow during obfuscation:

First i open create new project in dotfuscator.

In add input assembly i add myapp.exe and myapp.exe.config file from the bin folder of my project.

In build menu i select destination directory and click on build.

Now obfuscated file will be generated which i will use.

So please help me to solve this error.