Failed to encrypt the section 'appSettings'

Hello

Need some help, i have an application that always worked fine, in windows xp and in some machines that have windows 7.

Now the company bought some new machines that came with windows 7, in some of them my application fails to start with this error:

Quote:

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System.Configuration.ConfigurationErrorsException: An error occurred executing the configuration section handler for appSettings. ---> System.Configuration.ConfigurationErrorsException:
Failed to encrypt the section 'appSettings' using provider 'RsaProtectedConfigurationProvider'.
Error message from the provider: Object already exists.

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I found this link in the MS Connect, but when trying to run the command it says it misses webengine.dll... I'm assuming that this happens because it needs the IIS installed or something like that!?

So anyone has some info how to solve this?

Thanks