Openstack dashboard Error: Unable to retrieve usage information, instances - openstack

Question

I installed devStack on Ubuntu 16.04 LTS (installed in VirtualBox)
When I login into the dashboard I get this error (in the Overview tab) :
Error: Unable to retrieve usage information
I tried the solution that i found in the net, but no one of them work (a lot of them are deprecated, there is no ./rejoin-stack as as proposed in this solution)
The same problem when i press Instances i get :
Error: Unable to retrieve instances.
And for Volumes tab :
Error: Unable to retrieve volume list.
Error: Unable to retrieve snapshot list.
And for Images tab :
Error: Unable to retrieve images.
In Images tab :
Error: Unable to retrieve security groups.
Error: Unable to retrieve key pair list.
Error: Unable to retrieve floating IP addresses.
Error: Unable to retrieve floating IP pools.
this is my first time installing devStack, I don't know where to check !
I edited the local.conf file exist in devstack/samples, here is the content of the file :
# Sample ``local.conf`` for user-configurable variables in ``stack.sh``
# NOTE: Copy this file to the root DevStack directory for it to work properly.
# ``local.conf`` is a user-maintained settings file that is sourced from ``stackrc``.
# This gives it the ability to override any variables set in ``stackrc``.
# Also, most of the settings in ``stack.sh`` are written to only be set if no
# value has already been set; this lets ``local.conf`` effectively override the
# default values.
# This is a collection of some of the settings we have found to be useful
# in our DevStack development environments. Additional settings are described
# in http://devstack.org/local.conf.html
# These should be considered as samples and are unsupported DevStack code.
# The ``localrc`` section replaces the old ``localrc`` configuration file.
# Note that if ``localrc`` is present it will be used in favor of this section.
[[local|localrc]]
# Minimal Contents
# ----------------
# While ``stack.sh`` is happy to run without ``localrc``, devlife is better when
# there are a few minimal variables set:
# If the ``*_PASSWORD`` variables are not set here you will be prompted to enter
# values for them by ``stack.sh``and they will be added to ``local.conf``.
ADMIN_PASSWORD=nomoresecret
DATABASE_PASSWORD=stackdb
RABBIT_PASSWORD=stackqueue
SERVICE_PASSWORD=$ADMIN_PASSWORD
# ``HOST_IP`` and ``HOST_IPV6`` should be set manually for best results if
# the NIC configuration of the host is unusual, i.e. ``eth1`` has the default
# route but ``eth0`` is the public interface. They are auto-detected in
# ``stack.sh`` but often is indeterminate on later runs due to the IP moving
# from an Ethernet interface to a bridge on the host. Setting it here also
# makes it available for ``openrc`` to include when setting ``OS_AUTH_URL``.
# Neither is set by default.
HOST_IP=10.0.2.15
PUBLIC_INTERFACE=eth1
#HOST_IPV6=2001:db8::7
# Logging
# -------
# By default ``stack.sh`` output only goes to the terminal where it runs. It can
# be configured to additionally log to a file by setting ``LOGFILE`` to the full
# path of the destination log file. A timestamp will be appended to the given name.
LOGFILE=$DEST/logs/stack.sh.log
# Old log files are automatically removed after 7 days to keep things neat. Change
# the number of days by setting ``LOGDAYS``.
LOGDAYS=2
# Nova logs will be colorized if ``SYSLOG`` is not set; turn this off by setting
# ``LOG_COLOR`` false.
#LOG_COLOR=False
# Using milestone-proposed branches
# ---------------------------------
# Uncomment these to grab the milestone-proposed branches from the
# repos:
#CINDER_BRANCH=milestone-proposed
#GLANCE_BRANCH=milestone-proposed
#HORIZON_BRANCH=milestone-proposed
#KEYSTONE_BRANCH=milestone-proposed
#KEYSTONECLIENT_BRANCH=milestone-proposed
#NOVA_BRANCH=milestone-proposed
#NOVACLIENT_BRANCH=milestone-proposed
#NEUTRON_BRANCH=milestone-proposed
#SWIFT_BRANCH=milestone-proposed
# Using git versions of clients
# -----------------------------
# By default clients are installed from pip. See LIBS_FROM_GIT in
# stackrc for details on getting clients from specific branches or
# revisions. e.g.
# LIBS_FROM_GIT="python-ironicclient"
# IRONICCLIENT_BRANCH=refs/changes/44/2.../1
# Swift
# -----
# Swift is now used as the back-end for the S3-like object store. Setting the
# hash value is required and you will be prompted for it if Swift is enabled
# so just set it to something already:
SWIFT_HASH=66a3d6b56c1f479c8b4e70ab5c2000f5
# For development purposes the default of 3 replicas is usually not required.
# Set this to 1 to save some resources:
SWIFT_REPLICAS=1
# The data for Swift is stored by default in (``$DEST/data/swift``),
# or (``$DATA_DIR/swift``) if ``DATA_DIR`` has been set, and can be
# moved by setting ``SWIFT_DATA_DIR``. The directory will be created
# if it does not exist.
SWIFT_DATA_DIR=$DEST/data

Answer 1

After googling, seems like this is related to
No rejoin-stack.sh script in my setup
Which means devstack is not supposed to working after reboot

Answer 2

In the new version of devstack, the rejoin-stack.sh has been removed.
You can use the screen -c stack-screenrc.