Version 3.9.3 was specifically optimized to handle the major under-the-hood shifts in Apple's file system:
For users with mid-2010s MacBooks that max out at High Sierra or Mojave, this version is often the most stable performance optimizer available. CleanMyMac 3.9.3
If you are looking for the latest performance tools, you can find the current version at the official CleanMyMac website . Version 3
It resolved critical crashes and UI glitches that occurred when the older CleanMyMac 3 architecture met High Sierra’s new security layers. CleanMyMac 3.9.3
Before the app evolved into the more complex CleanMyMac X, the 3.9.3 version was praised for its balance of utility and speed: