Switching panel layouts using "Welcome" is buggy

[Gabriel]

When setting it to "Familiar", I get no panels.

When setting it to "Cupertino", I get errors loading applets with no name.

Other layouts have similar issues.

Sometimes, it creates a duplicate instance after changing it.

Setting it to "Mutiny" does work.

Changing it MATE Tweak works completely fine.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: ubuntu-mate-welcome (not installed)
ProcVersionSignature: Ubuntu 4.15.0-13.14-generic 4.15.10
Uname: Linux 4.15.0-13-generic x86_64
ApportVersion: 2.20.9-0ubuntu2
Architecture: amd64
CasperVersion: 1.392
CurrentDesktop: MATE
Date: Sun Apr 15 01:20:35 2018
LiveMediaBuild: Ubuntu-MATE 18.04 LTS "Bionic Beaver" - Beta amd64 (20180404)
ProcEnviron:
 TERM=xterm
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=C.UTF-8
 SHELL=/bin/bash
SourcePackage: ubuntu-mate-welcome
UpgradeStatus: No upgrade log present (probably fresh install)