If you are working on a project that includes connecting to legacy databases, you may get the CS1069 problem for OleDbConnection in Visual Studio. Missing references or problems with Visual Studio settings are frequently the cause of this issue. The problem is usually fixed by installing the System.Data.OleDb assembly, either manually or with NuGet. Additionally, for database connectivity, it can be important to make sure the right OLE DB provider is installed on your system. You can prevent future installation problems and restore functionality with these fixes.