OK, try again in 1.2.4. I fixed it. If you have any other issues, please report them. I haven't tested this, as it may be specific to your project or other plugins.
So, feel free to report any issues.
Open the Plugin Manager and ensure it loads after Core/VisuMZ (if applicable).
Clear the cache (Ctrl+F5) and run the test on the map with the balloon.

