ddhsoftware.com

After updating my MBP to OS catalina, an error message stating that it would not start was received. I have tried without success to contact the support team, but no responsive from them. Anyone else have this problem and if so, how have you solved it?

You posted to the Windows section not the MAC Desktop section, so you might not get responses.
I don't have CATALINA on my MBP, only El Capitan. I also had this problem that I posted on the MAC Desktop forum. Here is what I found. BTW, I saved my earlier desktop version (4.512) and installed the new version which gave the following result. Saved the new one just in case, but went back to using the 4.512 version which I continue to use and not updating to CATALINA until it works.

Re: Mac OS 64 Bit version
Postby glenwf » Thu Jan 16, 2020 2:59 pm
Got it and it runs,
BUT
I can not sync with my iPhone. When I select my iPhone and try to connect with the correct URL, I get this Message:

The resource could not be loaded because the App Transport Security policy requires the use of a secure connection.

I looked at :
Got to Apple->System Preferences->Security and Privacy
On the General tab, look at the bottom 3rd, and there should be something about HanDBase cannot be opened. There will be an 'Open Anyways' button. Click it.

But that does not relate to my system : OSX, El Capitan, 10.11.6, MacBook Pro (15-inch, Mid 2012),

I poked around and couldn't find anything except firewall stuff. Do I deactivate my firewall? NO, that didn't work.
Any Suggestions other than removing this update?