Hi voked, the current trial version, v3, is not compatible with Catalina OS and there is no way to make it work there because Apple completely removed support for 32-bit apps.

The next v4 release has undergone a major rewrite and is now 64-bit and will work fine on Catalina.

V4 is still in the process of being wrapped up, there will be one more beta release I think before it is finished. Currently v3 owners can download the v4 beta at http://moi3d.com/beta.htm .

For the v3 trial you would need to run it on Mojave or earlier to test it, it will not run on Catalina.

- Michael