With release 1.15 or xorg, the driver ABI has been bumped to version 8, and the latest available package from the Parallels tools is for 1.14. Please push out an update to us soon, we can't fix this ourselves like the kernel modules.
Unfortunately Parallels Tools indeed comes without support for Xorg 1.15 ABI, means Ubuntu 14.04 or any other distribution based on updated graphics stack will fail. Parallels support "elegantly" postponed resolution to somewhere in the future, I guess until official release of Ubuntu-14.04 Or Fedora-21.
