SSIS mySQL ADO.NET connection string
There are many things that can causes this issue:


You are running under 64Bit mode


in the project properties window, go to Debugging tab, and set Run64BitRuntime as false. and try again.


If SSIS Server and DEV Computer have different Connector/.Net Versions


This will occur after deployment


You are missing the provider in the connectionstring


You have to add ;Provider=MySQLProv or ;Provider=MSDASQL or other provider name (if you are not using these providers) to the connection string

References


https://stackoverflow.com/questions/18120800/ssis-error-could-not-create-a-managed-connection-manager-vs-2010-adonet
https://social.msdn.microsoft.com/Forums/sqlserver/en-US/392c89cb-19d1-48c8-8d54-e8ae0e75f8e8/could-not-create-a-managed-connection-manager-ssis-package-from-ssms-windows-7-64-bit?forum=sqlintegrationservices
https://www.connectionstrings.com/mysql/