Hello alberto.casadio and welcome to the forum.
I am sorry to hear about the problems you are running into.
You may not need the sounds updates; I am almost certain that they are incorporated into the main sounds download files. The updaters are there for users who downloaded the main files a long time ago.
You may be able to check this be extracting (UnZipping) the files in the update Content and comparing the files' "date modified" with those of the files in the MP2 sounds library.
As this is primarily a user to user forum, someone-else may chime in [#]. Or you could raise a
Support Ticket, here for some one to one investigation and help (US (East Coast) Business hours, generally). Response time is usually within 2 working days, but in the current circumstances please cut them some slack.
Also, let Support know that Catalina reported the updater file as dangerous. That needs fixing.