[Unit]
Description=My Service

[Service]
Type=simple
WorkingDirectory=/home/cobra/myx20service/
ExecStart=/home/cobra/myx20service/start.sh

[Install]
WantedBy=multi-user.target

Failed at step CHDIR spawning /home/cobra/my service/start.sh: No such file or directory
myservice.service: main process exited, code=exited, status=200/CHDIR

File: ‘/home/cobra/my service/start.sh’
  Size: 280             Blocks: 8          IO Block: 4096   regular file
Device: 903h/2307d      Inode: 4718912     Links: 1
Access: (0754/-rwxr-xr--)  Uid: ( 1000/   cobra)   Gid: ( 1000/   cobra)
Access: 2015-05-24 22:42:12.702657594 +0200
Modify: 2015-03-27 22:28:05.682531000 +0100
Change: 2015-05-24 22:40:58.830298787 +0200
 Birth: -

ExecStart="/home/cobra/my service/start.sh"

~$ systemd-escape --path "/home/cobra/my service/start.sh"
home-cobra-myx20service-start.sh