During the initial installation of leap 42.1, the following error shows up.
This prevents me from installing it.

Internal error. Please report a bug report with logs
Details: invalid byte sequence in UTF-8
Caller: /mounts/mp_0006/usr/share/YaST2/modules/InstFunctions.rb:150:in
`downcase`

This happens during the step "Search for system files". It is 100% repeatable.
Same error happens with tumbleweed.

Steps to repeat:
1. Download linux and initrd for 42.1
2. kexec downloaded kernel
3. Wait for reboot and installation to start.