This issue occurs due to an additional module in the Inbox driver that is not available in the Async driver. This causes an error in the upgrade process from Inbox driver to Async driver, resulting in a purple diagnostic screen failure.
The inbox rdma module must be removed before updating from the nmlx4_en 3.0.0.0 Inbox driver to the nmlx4_en 3.2.0.7 Async driver on ESXi 6.0/6.0U1. Upgrading without removing the rdma module can trigger the purple screen failure.