Just upgraded my Mac to OS X EL Capitan Public Beta. CCleaner Professional edition was running fine on the previous beta version but since upgrade is now refusing to work - displaying 'unsuported OS' - have i just wasted money upgrading to professional or will it return at some point?
Beta os are (as a rule) not always immediately compatible with software (of all kinds) as developers (of any software) need time to create differences (sometimes as simple as upping a hardcoded supported OS version number, sometimes much much more work) and thus piriform has never officially supported beta OS. That said, the developers read all threads and will have noted your concerns. They may not reply, unless they need more information from you, as this is the user forum. As a paid customer you are entitled to a year of priority, direct developer support so you, if you wish, might contact them directly (though I'm pretty certain you'll get a similar answer.