When I add using MySql.Data.MySqlClient; the following error message appears:
can not start debugging because the debug target 'c: \ users \ user \ documents \ visualstudio2018 \ Projects \ Application \ bin \ Debug \ Application.exe' is missing. Build the project and try again, or adjust the OutputhPath and AssemblyName properties appropriately to point to a correct location of the target assembly "Can sql problem with firewall? how to solve?