I'm glad I found this thread through a search engine; your steps worked for me, although with a few unexpected results along the way.
I also am a Tumbleweed user, and wanted to use CrossOver 19 to install several Win programs onto a desktop and a laptop. CrossOver issued now-forgotten error messages on the desktop when I attempted to install one day, then mysteriously behaved and finished installation a few days later.
On the laptop, I saw:
CrossOver needs your permission to install missing packages.
This operation must be run as root:
sh - c "sypper install gtk3 python3-gobject"
Trying with sudo ...
'gtk3' not found in package names. Trying capabilities.
'libgtk-3-0' providing 'gtk3' is already installed.
'python3-gobject' is already installed.
No update candidates for 'python3-gobject-3.34.0-3.3.x86_64'. The highest available version is already installed.
And then later:
Some errors may prevent CrossOver Linux from working correctly.
* Could not load the GObject-Introspection Python module.
* Could not load the Gobject-Introspection data for GTK.
You may be able to fix some issues by running one of the following commands as root:
openSUSE <= 11.2 zypper install gtk3 python3-gobject
Most importantly: it wouldn't work.
I discovered this thread and followed your steps. I used an .rpm CrossOver file, as that's what I had, saw some error messages on the sudo zypper install packages, and received an error message when I ran the cxfix command.
But, bottom line: CrossOver now works. Thanks for taking the time to post.