[gazebo-2] process has died [pid 18252, exit code 134, cmd /opt/ros/kinetic/lib/gazebo_ros/gzserver

[Masoumehrahimi]

Hi,
I run a navigation package with its launch file, previous it worked peoperly and there was not any issue. but know it shows the following error:
[INFO] [1612612822.036242, 0.000000]: Calling service /gazebo/set_model_configuration
Aborted (core dumped)
Service call failed: unable to connect to service: [Errno 104] Connection reset by peer
[gazebo-2] process has died [pid 18252, exit code 134, cmd /opt/ros/kinetic/lib/gazebo_ros/gzserver -u -e ode worlds/map_number4.world __name:
=gazebo __log:=/home/masoumeh/.ros/log/df0125aa-6872-11eb-b6b1-9cfce86bc641/gazebo-2.log].

Ubuntu 16
gazebo 7
would you please help me to solve this issue?
Thanks

[EmersonCassiano]

Hi! my error is: [gazebo-2] process has died [pid 27851, exit code 255, cmd /opt/ros/noetic/lib/gazebo_ros/gzserver -u -e ode
Solution:open terminal, copy and paste this ~> killall gzserver and killall gzclient