Hi,
I received this message when download mudfish 5.2.1 from your website, on mac os catalina 10.15.4, 5.2.0 working fine btw.
The Mudfish dev team is currently working on the issue.
Sorry for the inconvenience.
@glendonyeo Could you please test with http://mudfish.net/releases/mudfish-5.2.2.dmg file? We’d uploaded v5.2.2 for testing purpose.
it installed successfully but when I click dashboard it open blank page.
Ooops… 
Please test with http://mudfish.net/releases/mudfish-5.2.2.dmg link. I’d replaced a installer with new one.
ok. now I can open the dashboard. but I can’t connect to vpn. process stopped at 96%. I checked self-diagnosis and first item ‘Core process is ready’ is failed.
I’d updated the package again and tested that it works fine on my environment. Please test when you get a chance after downloading http://mudfish.net/releases/mudfish-5.2.2.dmg link.
Thank you for your testing!
it works thank you! 
It’s working as expected now, you can proceed to close the topic.
Thanks for the support.
Also update the new downloads to this version for Catalina!