SharePoint 2016 DB support - getting issues trying to fetch content using c# code

Trying to fetch the content using SharePoint 2016 database using C# code. Initially got error related to "clsid". So made the required entries on the Registory. However now getting the below exception. Have placed all the DLLs of 16 Hive folder still getting the issue:

System.Runtime.InteropServices.SEHException (0x80004005): External component has thrown an exception. at Microsoft.SharePoint.Library.SPRequest..ctor() at Microsoft.SharePoint.SPGlobal.CreateSPRequestAndSetIdentity(SPSite site, String name, Boolean bNotGlobalAdminCode, String strUrl, Boolean bNotAddToContext, Byte[] UserToken, SPAppPrincipalToken appPrincipalToken, String userName, Boolean bIgnoreTokenTimeout, Boolean bAsAnonymous) at Microsoft.SharePoint.SPRequestManager.GetContextRequest(SPRequestAuthenticationMode authenticationMode) at Microsoft.SharePoint.Administration.SPFarm.get_RequestNoAuth() at Microsoft.SharePoint.CoordinatedStreamBuffer.SPCoordinatedStreamBufferOnFile..ctor(Int64 offsetMax) at Microsoft.SharePoint.CoordinatedStreamBuffer.SPCoordinatedStreamBufferFactory.CreateEmptyRaw(Int64 cbHint) at Microsoft.SharePoint.CoordinatedStreamBuffer.SPCoordinatedStreamBufferFactory.CreateFromDocParams(SPMonitoredScope parentScope, SPBackgroundFillerManager fillerManager, SPDiagnosticsState diagState, SqlSession session, Guid guidSiteId, Int32 cbContent, Nullable1 parentId, Guid docId, Nullable1 level, SPChunkedArray1 rgbContent, Byte[] rgbRbsId, Int64 bsn, Byte partition, Int32 pageSize, Boolean bStartFilling, Nullable1 AbsId, Byte[] rgbAbsInfo) at Microsoft.SharePoint.CoordinatedStreamBuffer.SPCoordinatedStreamBufferFactory.CreateFromStreamParams(SqlSession session, Guid guidSiteId, Int32 cbContent, Guid docId, SPChunkedArray1 rgbContent, Byte[] rgbRbsId, Int64 bsn, Byte partition, Boolean bStartFilling, Nullable1 AbsId, Byte[] rgbAbsInfo) at Microsoft.SharePoint.CoordinatedStreamBuffer.SPCoordinatedStreamBufferFactory.CreateFromStreamRowset(SqlSession session, SqlDataReader dr, Boolean startFilling, Boolean bGetHash, SPDocumentStreamResult& stmResult) at Microsoft.SharePoint.CoordinatedStreamBuffer.SPCoordinatedStreamBufferFactory.CreateFromStreamRowset(SqlSession session, SqlDataReader dr, Boolean startFilling, SPDocumentStreamResult& stmResult) at Microsoft.SharePoint.SPFileStreamStore.GetBlobsById(List1 streamIds, Boolean doConsistencyCheck, DisposalEscrow dispEsc) at Microsoft.SharePoint.SPFileStreamHostBlobStore.ExecuteQuery(IEnumerable1 queries)