Extensions that were broken have since been fixed. Most extensions will continue working without needing updates from the developer. The software is compatible with previously saved MFA files, but once saved, cannot be opened in MMF2. Likewise with Multimedia Fusion 2, there are multiple editions of the software, sharing the same interface but have different runtime agreements and features.
It is the successor to Multimedia Fusion 2 and marks an end to the The Games Factory brand. Clickteam Fusion 2.5, or simply Fusion 2.5 is an upgrade from Clickteam featuring a highly optimised runtime and new exporters.
