[Koha] error on import Marc Record from z39.50 servers listed in Koha

[Mesfin Teshome]

Dear all,
I am continuing to have some challenges with Koha 3.12. Our librarians are facing some errors when they try to import Marc Records from z39.50 servers in Koha and save. Importing goes ok but when they click save Koha throws the error below. This behavior is not consistent. It happens with some books and does not happen with others. I tried searching and importing the Marc records for this books on Koha 3.8 and import and save works fine without an error.  The error Koha throws is: 
Software error:
Can't call method "data" on an undefined value at /usr/share/koha/lib/C4/AuthoritiesMarc.pm line 273.

Some of the books are:
	* The Political writings of St. Augustine
	* Calvin's Calvinism
What should I be looking at to troubleshoot this problem.