Segmentation fault with gnome-control-center on ubuntu 18

I was unable to open the settings tab of my ubuntu 18. This seems to be a very common issue as I found various threads on it with solutions ranging from asking to remove external ppas, reinstalling gnome-control-center etc. However none of this worked.

Finally I ran gnome-logs from the terminal and saw the detailed segmentation fault error under the System tab: 

gnome-control-c[28768]: segfault at fffffff8 ip 00007fe6cc71c8a0 sp 00007ffdf553f9e0 error 4 in libc-2.30.so[7fe6cc6a4000+178000]

On searching for error 4 libc along with gnome-control-center segmentation fault, I found the following page which finally solved the issue for me, at least temporarily.

https://bugzilla.redhat.com/show_bug.cgi?id=1668792

Removing the "user" file from .config/dconf folder made gnome-control-center work again!

Running arduino board with ubuntu 18 and ros melodic

While trying to run arduino script using rosserial_python serial_node.py, I was getting following error:

[ERROR] [1598864453.982391]: Unable to sync with device; possible link problem or link software version mismatch such as hydro rosserial_python with groovy Arduino

The error was occuring because my rosmsg type was Float32MultiArray which contains an array inside it. Probably this leads to some buffer overflow in ros melodic which causes the error. Changing the rosmsg type to Point from Float32MultiArray solved the issue for me. 

Other things that helped in running arduino board with ubuntu and ros melodic were:

1) Make the usb port writable. Solution is provided at https://arduino.stackexchange.com/questions/21215/first-time-set-up-permission-denied-to-usb-port-ubuntu-14-04 

2) Make sure pubsub example in ros_lib is working. Solution is provided at https://answers.ros.org/question/360537/unknown-error-handler-name-rosmsg/

3) Only baud rate of 57600 worked with ros