JCH Optimize and others

If you are using a caching optimizer like the JCH Optimize plugin, you have to exclude leaflet.js from optimization.

Here is how to do:

Go to the Joomla-menu 'Extensions', select 'Plugins' from this menu, search for "JCH Optimize", click this plugin, select the tab 'Exclude Options', scroll to the part 'Exclude files and extensions from aggregation' and in the field 'Exclude JavaScript Files' enter "leaflet.js" (without the quotes), then click the button 'Add item' and click the button 'Save' on top of the screen to save the plugin settings.

Other Cache Optimizers have a similar way of excluding files from processing.

Many thanks to Arjan Myer for investigating the problem.