I created a trigger that on a record creation (Custom sObject), subscribes all the createdBy role members to the record.
This code seems to work just fine when executed by a sys admin, but it throws the following error for a user with Chatter Only profile.
Insert failed. First exception on row 0; first error: INSUFFICIENT_ACCESS_ON_CROSS_REFERENCE_ENTITY, insufficient access rights on cross-reference id: 
What I'm missing here ??