Encryption Error, don't know how to address it or what the error is PLEASE HELP

Error Description: Unprotect data exception. ExStackTrace: at NCrypto.Security.Cryptography.ProtectedData.Unprotect(Byte[] encryptedData, Byte[] optionalEntropy, DataProtectionScope scope)

at NCrypto.Security.Cryptography.ProtectedData.Unprotect(Byte[] encryptedData)

at ac.RegistryCryptoUtility.DecryptRegistryConnectionString(String configConnectionSetting) in c:\inetpub\wwwroot\AC\common\Encrypt.vb:line 75

 

I'm receiving the following error above and I don't really know what is causing the error to occur.  There isn't much help online I've found.  Basically we're encrypting connection strings and recently got this error.

 

PLEASE HELP.
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