Mirroring: "Object reference not set to an instance of an object" at validating mirroring settings

Found in

EPiServer.CMS.Core 10.2.0

Fixed in

EPiServer.CMS.Core 10.3.2


Dec 30, 2016


Apr 11, 2017


CMS Core


Closed, Fixed and tested


Steps to reproduce:
1. Upgrade a 7.5 CMS site to
2. Configure mirroring for mirror from Page1 to Page2 -> mirroring settings are valid and its function runs properly.
3. Upgrade to CMS Core 10.2.x.
4. Open Config > Mirroring > check system for the mirroring settings

Expected: Validation is OK
Actual: Error message appears in Messages column as "Object reference not set to an instance of an object." (this error message is not clear/informative for users while no log is written in log file)
Observed: After upgrading to Core 10.3.0, this bug is not seen but QA can't make sure that it may occur again after fixing the bug CMS-5997