There's a few antivirus products that are not playing nice with VMware.
AVG, BitDefender and Avast come to mind.
Have a look at the following thread to see if you can mitigate the issue by making a change to some settings.
Wil| Author of Vimalin. The virtual machine Backup app for VMware Desktop Products
| Vimalin : Automated backups for VMware Fusion and VMware Workstation Professional
| More info at https://www.vimalin.com
| Twitter @wilva
| VMware Wiki at http://www.vi-toolkit.com
I removed AVG and switched to ESET - problem solved although still unknown.