Thanks for the feedback.
This below is the complete error message on the cpntroller:
Redundancy Toggle ->Prim (Failure) 29.03.17 15:53:27.435
263 _stc : Error 0x80000312 in Network Line 2 29.03.17 15:53:13.275
262 RRCV : Error 0xFFFF03A7 in REDBTR.d Line 3754 29.03.17 15:53:06.811
261 EAID : Error 0xFFFF0F00 in EAOBJ.d Line 1182 29.03.17 15:53:06.691
260 EARE : Error 0xFFFF0F00 in EAOBJ.d Line 1134 29.03.17 15:53:06.691
The issue that we have is that there are some export variable that this controller can not read from other controllers.
The error codes indicate that the redundancy connection is canceled, that's why the redundancy toggle failure.
What is the version of your system? There are many information about similar issues detected but it depend of the system version.
Additional, to the reference indicate by Henkel, you can check the Product Bulletin F0251 "Freelance: Stop of Lateral Communication after cold start or redundancy fail over"