VMware has released a big patch for ESXi 6.0 a few days ago which addresses many nasty outstanding issues, including the most recent CBT issue with taking quiesced VM snapshots with VMware Tools VSS, as well as a few PSOD conditions. Especially useful for Veeam B&R that leveraging VMware Changed Block Tracking (CBT) data supplied (Backup and Replicas of virtual machines running on ESXi 6.0.x). You can find more information about the patch here.
Patch Download and Installation:
An ESXi system can be updated using the image profile, by using the “esxcli software profile” command. For details, see the vSphere Command-Line Interface Concepts and Examples and the VMware vSphere Upgrade Guide. ESXi hosts can also be updated by manually downloading the patch ZIP file from the “Patch Manager Download Portal” and installing the VIB by using the “esxcli software vib” command.
You can learn more about the Knowledge Base here.
You can learn more about Veeam Backup & Replication 9.5 here.