Reinstalling Parallels 9 and applying the patch is working on Yosemite DP6. Installing Parallels 10 still fails even after that though. DP7 of Yosemite popped up on my system today and I still can't install Parallels 10 after upgrading my system to Yosemite DP7 Eugene - any news from the Parallels team? This is dragging out a bit now with no new information.
I have just had my support call with Victoriya from the Parallels team and the issue was resolved perfectly. The problem on my system was due to a legacy user ID installed by MacPorts under a previous version of OS-X. For reasons known only to MacPorts they had created a User called macports with a UID of 0 which should be reserved for root. Victoriya spotted this using the command dscl . -list /Users UniqueID in the terminal window. I deleted the user using the Workgroup Manager tool but could have delete it in the terminal using dscl . -delete "/Users/macports" After deleting the bad user the install went perfectly. It's worth taking a look at the users registered on your system if you are having this problem. If you have an odd user with the UID 0 then deleting it will probably resolve your issue too. Many thanks to Eugene for setting up the support and to the exceptional helpful and capable Victoriya for spotting the problem so quickly and efficiently.
Glad to hear that Paul! And thank you for your valuable feedback. Feel free to contact us anytime, we are happy to help you!