Running 10.11 in VM Ware Fusion with 10.10 Host
El Capitan is a beta software and VMware Fusion 7.1.2 doesn't support El Capitan officially.

Just download and install VMware Fusion Technology Preview 2015 and try your luck.

Improvements among others:


New OS Support including Windows 10 Insider Preview and El Capitan Beta
DirectX 10 and OpenGL 3.3 Support