VMware Snapshot failing

We are using VMware ESXi 6.0.0 and are having trouble snapshotting some of the VMs with more than one disk in different datastores.
The error we are seeing in the VM logs is as follows:

2017-08-12T22:00:15.627Z| vmx| I125: SNAPSHOT: SnapshotPrepareTakeDoneCB: Prepare phase complete (The operation completed successfully).
2017-08-12T22:00:15.838Z| vcpu-0| I125: ToolsBackup: changing quiesce state: IDLE -> STARTED 2017-08-12T22:01:03.936Z| vmx| I125: Msg_Post: Warning
2017-08-12T22:01:03.937Z| vmx| I125: [msg.snapshot.quiesce.vmerr] The guest OS has reported an error during quiescing.
2017-08-12T22:01:03.937Z| vmx| I125+ The error code was: 5
2017-08-12T22:01:03.937Z| vmx| I125+ The error message was: 'VssSyncStart' operation failed: IDispatch error #8455 (0x80042307)
2017-08-12T22:01:03.937Z| vmx| I125: ----------------------------------------
2017-08-12T22:01:03.940Z| vmx| I125: Vigor_MessageRevoke: message 'msg.snapshot.quiesce.vmerr' (seq 24429073) is revoked
2017-08-12T22:01:03.940Z| vmx| I125: ToolsBackup: changing quiesce state: STARTED -> ERROR_WAIT
2017-08-12T22:01:14.090Z| vmx| I125: ToolsBackup: changing quiesce state: ERROR_WAIT -> IDLE 2017-08-12T22:01:14.091Z| vmx| I125: ToolsBackup: changing quiesce state: IDLE -> DONE
2017-08-12T22:01:14.091Z| vmx| I125: SnapshotVMXTakeSnapshotComplete: Done with snapshot 'smvi_743eb0f4-ca06-4237-a04d-eb92714ff4f2': 0
2017-08-12T22:01:14.091Z| vmx| I125: SnapshotVMXTakeSnapshotComplete: Snapshot 0 failed: Failed to quiesce the virtual machine (31).
2017-08-12T22:01:14.091Z| vmx| I125: VigorTransport_ServerSendResponse opID=626f5449-28-0da6 seq=612215: Completed Snapshot request.

When manually taking a snapshot from vSphere, selecting the Quiesce guest file system and Snapshot the virtual machine's memory options results in a successful snapshot. Unchecking the Snapshot the virtual machine's memory results in a failure. When checking in the Tasks & Events tab, the error says

An error occurred while saving the snapshot: msg.snapshot.error-QUIESCINGERROR.

Further investigation into this message shows that VMware Tools is not available.
The version of VMware Tools used is the same for all VMs - 10.1.5 build 5055683.

We have a number of backup jobs running, most are working fine, the exceptions to this are the VMs with multiple disks which are failing with the quiescing error.

WMare have suggested that downgrading Tools to version 10.0.9 may resolve the problem as they have seen similar symptoms in other reported problems and the downgrade has worked. I have created a brand new VM today with two disks on separate datastores, installed Tools 10.1.5, and included it in the problematic backup job. This VM has becked up successfully.
To add to the confusion, we had reinstalled Tools 10.1.5 on an existing VM to see if this made a difference and this VM is also now backing up with no problem so we tried to reinstall Tools on another VM. Tools reinstalled with no problem but the VM is still failing the backup with the quiescing error.
Can anyone help? This is turning out to be a real head-scratcher!

Thanks in advace.