Process is below: 1. I can successfully navigate to add-ins and choose and add-in to download 2. I can successfully click Add to Thunderbird 3. The screen in the attachment below is shown 4. I cannot get past this screen. If i click Add nothing happens and Thunderbird eventually shuts down. I am using Debian Linux in a virual env on chromebook currently on version 115.10.1 (64-bit) of thunderbird. Need to be able to download TBSYNC and the appropriate add-ins to get caldav and Exchange active sync to work. PLEASE HELP :)