I have a trial version of Sony Vegas, but I can't start any videos. Every time I get this error

VEGAS Pro 18.0
Version 18.0 (Build 482)
Exception 0xC0000005 (access violation) WRITE:0x0000000000000000 IP:0x0000000000000000
In Module 'vegas180.exe' at Address 0x0000000000000000 + 0x0000000000000000
Thread: VideoRender ID=0x1770 Stack=
How can I fix it?