Java – non existent MySQL message error

I have to build a decision support system, but I don't have much experience in Java Therefore, after I connected to MySQL using eclipse (using connector / J), eclipse began to mess up my other projects Now, when I try to run other projects in eclipse (not related to MySQL, such as guessing games), the following error message displays:

Launch configuration DocsConnectionPropsHelper references non-existing project MysqL connection test.

Can someone help me solve this problem?

UPDATE. It seems that when I press "run", elcipse doesn't run the project I'm using, but something else

Solution

Your update shows that the problem is actually running the wrong project To avoid this, you may want to close items you are not working on (right-click them in the package browser and select close)

If you really need to open multiple projects, when you click the run icon (rerun by default any project last run in the open project), make sure that the project that can be run is opened in the editor window (and from the project you want to run)

Then click the drop-down arrow to the right of the icon This opens a small menu with options to change the build configuration or how to run the program (that is, as an application or server)