There's no need to use a <Data Source> trigger, since you've setup the default data source, jdbc/Mainjdbc, to access MySQL.
The trigger is only needed when you've setup additional data sources, and only when accessing these additional data sources.
Remove the trigger and Find (and all other database plugins) should access your MySQL database.
Regardless, the second error you mention is a known bug, which I hope will be handled soon.
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