I had a similar query - registers in the datasheet that say can only be read with firmware 3.14 and above. The firmware in my device is 3.11. The solution in the posts reference a link to a firmware update that is not available now. Please can you make that available to me?
The latest FW of BNO055 can always be got from our website:
How to upgrade the FW:
1. The Development Desktop UI provided by BST includes the BNO055 FW upgrade function by default. You can use it to upgrade the BNO055 at your side
2. Adding the FW upgrade capability on your own board, this can refer to the previous comment in this ticket