Cryptograhy errors in TraceExpertSystem

If you encounter errors in the TraceExpertSystem.txt logs such as the following, you might have a problem with the MachineKeys on the system. This might present itself as the MWExpertSystem service failing to start.

2020/06/24 09:24:52 [5] FATAL MWExpertSystem.Main - ------AN UNHANDLED EXCEPTION HAS OCCURRED------
 
2020/06/24 09:24:52 [5] ERROR MWExpertSystem.Main - Exception 
System.Security.Cryptography.CryptographicException: Access is denied. 
   at System.Security.Cryptography.CryptographicException.ThrowCryptographicException(Int32 hr) 
   at System.Security.Cryptography.Utils._GenerateKey(SafeProvHandle hProv, Int32 algid, CspProviderFlags flags, Int32 keySize, SafeKeyHandle& hKey) 
   at System.Security.Cryptography.Utils.GetKeyPairHelper(CspAlgorithmType keyType, CspParameters parameters, Boolean randomKeyContainer, Int32 dwKeySize, SafeProvHandle& safeProvHandle, SafeKeyHandle& safeKeyHandle) 
   at System.Security.Cryptography.RSACryptoServiceProvider.GetKeyPair() 
   at LPI.Security.Cryptography.KeyGenerator.GenerateRandomAsymmetricKeyPair() 
   at LPI.Security.Cryptography.RandomKeyHierarchyContainer.EstablishHierarchy(Guid installationID) 
   at LPI.Security.OM.Cryptography.OnsiteManagerKeyContainer.EstablishHierarchy(Guid installationID) in c:\Builds\73\Sources\OMSolution.root\OMSolution\LPI.Security.OM\Cryptography\OnsiteManagerKeyContainer.cs:line 49 
   at LPI.ExpertSystem.ManagerNS.Manager.Init() in c:\Builds\73\Sources\OMSolution.root\OMSolution\LPI.OM.ExpertSystem\Main.cs:line 265 
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx) 
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state) 
   at System.Threading.ThreadHelper.ThreadStart()

This error occurs in the common decryption and encryption methods that use RSA. There are a variety of reasons an exception can be thrown, most of them having to do with inadequate permissions for the application on a folder.

1. Navigate to C:\ProgramData\Microsoft\Crypto\RSA
2. Right-click the MachineKeys folder and choose Properties.
3. Switch to the Security tab.
4. Select the Administrators group and check Allow for Full Control.
5. Select the Everyone group and check Allow for Full Control.
6. Click OK.
7. Restart MWExpertsystem Service