SPC-OCC-11818: Model Write Failed: The <attr_name> attribute cannot be modified because it is locked by a policy defined in Policy Manager
Release : 10.4.1
Component : Spectrum Core / SpectroSERVER
Two possibilities:
1) modify the <attr_name> via Policy Manager for that rule, but in this way you will modify that attribute threshold for all interfaces present in that GC, so you can do it only if you want to change the <attr_name> attribute for all members of that GC or
2) modify the dynamic GC search rule so that the specific interface you want to modify its <attr_name> threshold value is not automatically included in that GC. Basically you should exclude that interface from the GC so that the Policy Rule defined is not applied on it and you can set for it a different threshold value.