For clarification, is this a group here in the Jive Community or within your Jive instance?
If here on the Jive Community, can you please provide the URL for the group?
If in your Jive instance, please submit a case in your secret customer group here in the Jive Community so that the next available support engineer can assist with further investigations. When you submit the case, if you could include the following, it should help in their investigation:
1. The username you are seeing the behavior with
2. A link to the group where you are seeing the error