Looking closely at the versions involved in an RPM conflict can help you find a resolution.
Please keep in mind that the investigation, diagnoses, and resolution of issues caused by RPM conflicts are best handled by a systems administrator with the skills, training, and expertise required to do so for you.
Given the following error:
Error: Package: libcom_err-devel-1.42.9-11.el7.x86_64 (CentOSrepo)
Requires: libcom_err(x86-64) = 1.42.9-11.el7
Installed: libcom_err-1.42.9-12.el7_5.x86_64 (@updates)
libcom_err(x86-64) = 1.42.9-12.el7_5
Available: libcom_err-1.42.9-11.el7.x86_64 (CentOSrepo)
libcom_err(x86-64) = 1.42.9-11.el7
It may be possible to resolve the conflict by downgrading libcom_err-1.42.9-12 to the required version of libcom_err-1.42.9-11 .
Then attempt the previous action again.