ERROR: cannot launch node of type [explore_lite/explore]: Cannot locate node of type [explore] in package [explore_lite].

[lisacian]

Hi! I hope someone can help me solve this problem:

ERROR: cannot launch node of type [explore_lite/explore]: Cannot locate node of type [explore] in package [explore_lite]. Make sure file exists in package path and permission is set to executable (chmod +x)

I installed explore_lite using the command:
sudo apt install ros-${ROS_DISTRO}-multirobot-map-merge ros-${ROS_DISTRO}-explore-lite

I tried changing the permissions:
/opt/ros/melodic/lib/explore_lite$ sudo chmod +x explore
but I had no luck.

I'm using ROS melodic and move_base works without troubles. I updated all the packages, uninstalled and reinstalled ROS.. nothing works :(
My classmates are using the same version of ROS and didn't have any issue with this package.

Thanks in advance,
Lisa :)