Karune announced there will be changes to the JASS functionality in the next WarCraft III patch that map makers need to be aware of in order to make their old maps functional.  Otherwise, the maps won’t work at all, or may not work correctly.

Welcome Developers,

This guide has been written to help advanced Warcraft III map developers understand the changes that we’ve made to the JASS functionality. Please note that these changes apply to only a small set of custom map developers, and most Warcraft 3 custom maps remain unaffected. For those developers whose maps are affected by the changes we’ve made, please review the steps below to understand how to bring your map into compliance with our new implementation.

Note: JASS-enabled maps that are not brought into compliance with the may not work correctly or at all after we release the next Warcraft III patch.

Details on our new implementation: