You might try to work around this issue temporarily, you can disable the PT Auto Update mechanism following these steps:
IMPORTANT
Proceed at your own risk, you should know what you are doing, if you have any question or doubt regarding these instructions then don't do it, incorrectly editing the config.pvs may result in the loss of data, backup your VM first.
1) Shutdown the the Virtual Machine, it shouldn't be suspended or running.
2) Go to the .pvm package if the VM in Finder -> right click on it -> Show Package contents
3) Find the config.pvs file and open config.pvs in any text editor, for example TextEdit.
4) Find "<AutoUpdate.......>
<Enabled>1</Enabled>
</Autoupdate>"
5) Change the value in "Enabled" from 1 to 0: i.e "<Enabled>0</Enabled>"
6) Save the changes and exit the text editor.
By doing this, the Parallels Tools won't check for update.
You should revert these changes once a new Parallels Desktop update is released (change the value back to 1).
To be more precise, this disables the mechanism by which PT checks if the PT version installed is the same as the one in Parallels Desktop and autoupdates if not, might or might not workaround this issue, please share your experience.