Guess what happens if you open a project with a mysql database inside and you don't have the mysql plugin installed?
Answer: first nothing, but as soon as you double click the database, you get a failed assertion. Of I'd expect a nice dialog telling me that I need to add the plugin and if I don't have it, where I get it. In a perfect world, REAL Studio would simply download that plugin, install it and load it.
Well, if you like to comment on this: Feedback Report 14247