I experienced the same after loading the 5.1.37 JDBC driver for mySQL.
First, be sure to *reboot* your platform after installing in order to clear out stale objects - this is required as I learned yesterday.
Then after the reboot here is the confusing thing.
I too experience the exact same error when building a Database Thing using the 5.1.37 thing template.
*However* now when I use the standard "Database" thing template to create a Database Thing with a Query Service it works.
Based on that observation, can you try to build a test Database Thing based on the "Database" template and see if it works?
I know it doesn't explain why the 5.1.37 JDBC driver still doesn't work but at least it may get you further along in your project.
Please reply and let the forum know how it turns out.
Also note that once your database configuration is correctly set in the Database Thing that the table objects will show up in the Tables/Columns tab when creating a Service. In this example, a MySQL database with three tables.
JDBC Driver Class Name: com.mysql.jdbc.Driver
JDBC Connection String: jdbc:mysql://<database host:port/database name
Fill the Database User Name and Database Password
Hope this helps.