Hello,
I just installed Antix15 over the existing Antix13:
- I kept the home partition with the same login user
- I overwrote the root
- I changed to automatic login (same user as per Antix13)

1. Chromium indicated in"internet" dont start anymore
2. In the Roxterm, a lot of icons are missing and the exit button is not working.
3. A second"sound" icon right below appear now.
4. the conky is not so nice (no transparency despite the file say YES)
Any advice is welcome what to do.
It seems old files are still there and disturb.

yes, keeping your home folder will leave back all kinds of menu files and other configuration info. Between antiX 15 and 13, there is a bid difference in how startup files are handled. in 13, startup was in various window manager startup files. In 15, by default, startup is handled by a desktop-session wrapper script, including things like conky launch and the volume icon in the systray. Since you kept your home folder, you've likely got a lot of stuff left over from the previous 13 installation.

since you overwrote root (of course!) then items in the menu may be be available. The old menu files are not quite dynamic, but actually written out menu text files in your home folder. So you've probably got entries for apps that aren't installed.

My suggestion is copy your personal files over to a seperate folder outside your home folder, create a new user, and then bring those files into the new home folder. that should bring in all the config stuff you are missing, as well as get your menu correct.

You can always add a user, login as the new user, use root to remove old account. then create new accout with your usual username. You can use"Manage Users" in the Control Center to do all the account creation and removal. Just don't remove the account you are currently logged in!

THANKS.
In fact, installed again Antix15 and created a new user"xxxx" (and did not use the previous antix13 user).
Then I deleted all files of the previous user (after moving the usefull ones to"xxxx").
Now, when I log into"xxxx", everything looks fine.

Issues (new):
a)"use root to remove old account": the application"root terminal" is asking for the root PW, but it dont open. I have to use"su" command in a standard terminal of user"xxxx" and give the root password. It works. So, the"root terminal" application is not working for me.
b) ..."Manage Users" in the Control Center to do all the account creation and removal.. when I click on it, it ask the root password, but dont start. Its a like a). So, that application"Manage Users" dont work.

There are a few inconsistencies in control center. Try your user password instead of root. This is a change from 13.