CentOS7.5安装xfce4出错，导致GUI不能登录

CentOS7.5.1804下，执行下列命令后，导致GUI不能登录；输入用户名和密码后，反复进入登陆界面。

sudo yum install xfce4 xfce4-terminal vnc4server

在SSH终端，执行下列命令后，卸载后，还是不行。

sudo yum remove xfce4 xfce4-terminal vnc4server

在home目录行命令后"grep -rn xfce4"，把.cache目录改名，相当于删除相关文件。

[hankf@localhost ~]$ grep -rn xfce4
Binary file .cache/tracker/meta.db-wal matches
.cache/gnome-software/3.22/ratings/odrs.json:44993:    "xfce4-appfinder.desktop": {
.cache/gnome-software/3.22/ratings/odrs.json:45002:    "xfce4-clipman.desktop": {
.cache/gnome-software/3.22/ratings/odrs.json:45011:    "xfce4-dict.desktop": {
.cache/gnome-software/3.22/ratings/odrs.json:45020:    "xfce4-mime-settings.desktop":
.cache/gnome-software/3.22/ratings/odrs.json:45029:    "xfce4-notes.desktop": {
.cache/gnome-software/3.22/ratings/odrs.json:45038:    "xfce4-notifyd-config.desktop":
.cache/gnome-software/3.22/ratings/odrs.json:45047:    "xfce4-power-manager-settings.d": {
.cache/gnome-software/3.22/ratings/odrs.json:45056:    "xfce4-run.desktop": {
.cache/gnome-software/3.22/ratings/odrs.json:45065:    "xfce4-screenshooter.desktop":
.cache/gnome-software/3.22/ratings/odrs.json:45074:    "xfce4-sensors.desktop": {
.cache/gnome-software/3.22/ratings/odrs.json:45083:    "xfce4-taskmanager.desktop": {
.cache/gnome-software/3.22/ratings/odrs.json:45092:    "xfce4-terminal-settings.deskto
.cache/gnome-software/3.22/ratings/odrs.json:45101:    "xfce4-terminal.desktop": {
Binary file .local/share/tracker/data/tracker-store.journal matches

再执行下列命令。

yum update -y

最后重新启动，能再次从GUI界面登录。