This “Your conference request can’t go through because the agent doesn’t have view access” exception is thrown when the agent is trying to transfer to an user who doesn’t have access to the Chat Transcript record.

To fix this issue, the user to be on the Chat Conference should have view access to the Chat Transcript object/entity.

Quick Work Arounds:

1. Give View All access in the profile for the Chat Transcript object/entity.

2. Set the OWD for the Chat Transcript object/entity to Public Read-Only.