I try to install leap on a machine with Tumbleweed installed. 
This machine has three disc.
sda
sdb
sdc

The sda holds Tumbleweed with /sda1 as /boot and /sda2 as encryped LVM both
with EXT4. Boot loader is Grub2 with password. After the recent updates
everything is fine with this. 

sdb holds one encrypted partition with XFS for the entire disk. 

sdc should hold leap and has been erased to 0 partitions, virgin prior to
install. 

During install I give the installer all passwords for unlocking. 
I choose to use sdc as disc to install leap. 
I change to ext4 setup with encrypted LVM, /boot on sdc1 and /LVM on sdc2 as
proposed by the installer. 

I set here also password protected Grub2 in /boot on sdc1. 
When I want to install the installation fails reliably with the following error
(translated from Italian but should be understandable).

System error during the following operation.
While removing the system volume group LVM_VG_REMOVE_FAILED. 
Error code was -4013
/sbin/vgrepremove -f 'system' 
connect failed 
no such file or directory
warning failed to connect to lvmetad
falling back to internal scanning
Continue despite this error. 

Now, before I did try to continue but you get a non working system. /boot is
created but /system is empty in that case. 

After the install the other partitions are unchanged and tumbleweed does boot
perfectly, so at least now trouble with that. But I do not manage to install
Leap with this setting.