I work for a university. We are currently running 5.1 with several pools running linked clones. We recently started running across this error intermittently. The pools are set to PCoIP by default, and we disable the ability to select the protocol. When the message started occurring, we followed the suggestions here and would reboot the offending VM. Up until today that would resolve the issue. Today, however, we came across the issue for a coach that rebooting did not resolve. Upon further research I was able to determine that his linked clone VM was maxed out in the C:\. Through process of elimination I was able to narrow it down to C:\Windows\SysWOW64\config\systemprofile\AppData\Local\Microsoft\Windows\Temporary Internet Files. In that folder were over 250k files that took up almost 40GB of data. Preliminary googling indicates that this may be virus related. Recomposing resolved the issue.
We do not run disposable disks currently. In fact, we just recently redesigned our pool configuration to eliminate the disposable disk entirely.