I can’t enable or disable a user service: Failed to execute operation: No such file or directory

I want to debug/test a program in eclipse that uses a Redis server so I decided to turn the server into a user service to have the privilege of running it. What bothers me is that I can start or stop the service but not enable/disable it.

The error I get is:

Failed to execute operation: No such file or directory

Original /usr/lib/systemd/system:

[Unit]
Description=Advanced key-value store
After=network.target

[Service]
User=arkos
ExecStart=/usr/bin/redis-server /etc/arkos/arkos-redis.conf
ExecStop=/usr/bin/redis-cli shutdown

[Install]
WantedBy=multi-user.target

Edited and moved to /usr/lib/systemd/user:

[Unit]
Description=Advanced key-value store

[Service]
ExecStart=/usr/bin/redis-server /etc/arkos/arkos-redis.conf
ExecStop=/usr/bin/redis-cli shutdown

[Install]
WantedBy=default.target

Systemctl status:

�� arkos-redis.service - Advanced key-value store
   Loaded: loaded (/usr/lib/systemd/user/arkos-redis.service; disabled; vendor preset: enabled)
   Active: active (running) since Tue 2015-08-25 09:19:25 UTC; 1min 55s ago
  Process: 644 ExecStop=/usr/bin/redis-cli shutdown (code=exited, status=1/FAILURE)
 Main PID: 736 (redis-server)
   CGroup: /user.slice/user-1000.slice/user@1000.service/arkos-redis.service
           ������736 /usr/bin/redis-server *:0                        

Aug 25 09:19:25 arkos-vagrant redis-server[736]: |    `-._`-._        _.-'_.-'    |
Aug 25 09:19:25 arkos-vagrant redis-server[736]: `-._    `-._`-.__.-'_.-'    _.-'
Aug 25 09:19:25 arkos-vagrant redis-server[736]: `-._    `-.__.-'    _.-'
Aug 25 09:19:25 arkos-vagrant redis-server[736]: `-._        _.-'
Aug 25 09:19:25 arkos-vagrant redis-server[736]: `-.__.-'
Aug 25 09:19:25 arkos-vagrant redis-server[736]: 736:M 25 Aug 09:19:25.471 # Server started, Redis version 3.0.3
Aug 25 09:19:25 arkos-vagrant redis-server[736]: 736:M 25 Aug 09:19:25.472 # WARNING overcommit_memory is set to 0! Background save may fail under low memory condition. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect.
Aug 25 09:19:25 arkos-vagrant redis-server[736]: 736:M 25 Aug 09:19:25.472 # WARNING you have Transparent Huge Pages (THP) support enabled in your kernel. This will create latency and memory usage issues with Redis. To fix this issue run the command 'echo never > /sys/kernel/mm/transparent_hugepage/enabled' as root, and add it to your /etc/rc.local in order to retain the setting after a reboot. Redis must be restarted after THP is disabled.
Aug 25 09:19:25 arkos-vagrant redis-server[736]: 736:M 25 Aug 09:19:25.472 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sys/net/core/somaxconn is set to the lower value of 128.
Aug 25 09:19:25 arkos-vagrant redis-server[736]: 736:M 25 Aug 09:19:25.472 * The server is now ready to accept connections at /tmp/arkos-redis.sock

Journalctl:

Aug 25 09:19:25 arkos-vagrant redis-server[736]: 736:M 25 Aug 09:19:25.470 # You requested maxclients of 10000 requiring at least 10032 max file descrip
Aug 25 09:19:25 arkos-vagrant redis-server[736]: 736:M 25 Aug 09:19:25.470 # Redis can't set maximum open files to 10032 because of OS error: Operation 
Aug 25 09:19:25 arkos-vagrant redis-server[736]: 736:M 25 Aug 09:19:25.470 # Current maximum open files is 4096. maxclients has been reduced to 4064 to 
Aug 25 09:19:25 arkos-vagrant redis-server[736]: _._
Aug 25 09:19:25 arkos-vagrant redis-server[736]: _.-``__ ''-._
Aug 25 09:19:25 arkos-vagrant redis-server[736]: _.-``    `.  `_.  ''-._           Redis 3.0.3 (00000000/0) 64 bit
Aug 25 09:19:25 arkos-vagrant redis-server[736]: .-`` .-```.  ```\/    _.,_ ''-._
Aug 25 09:19:25 arkos-vagrant redis-server[736]: (    '      ,       .-`  | `,    )     Running in standalone mode
Aug 25 09:19:25 arkos-vagrant redis-server[736]: |`-._`-...-` __...-.``-._|'` _.-'|     Port: 0
Aug 25 09:19:25 arkos-vagrant redis-server[736]: |    `-._   `._    /     _.-'    |     PID: 736
Aug 25 09:19:25 arkos-vagrant redis-server[736]: `-._    `-._  `-./  _.-'    _.-'
Aug 25 09:19:25 arkos-vagrant redis-server[736]: |`-._`-._    `-.__.-'    _.-'_.-'|
Aug 25 09:19:25 arkos-vagrant redis-server[736]: |    `-._`-._        _.-'_.-'    |           http://redis.io
Aug 25 09:19:25 arkos-vagrant redis-server[736]: `-._    `-._`-.__.-'_.-'    _.-'
Aug 25 09:19:25 arkos-vagrant redis-server[736]: |`-._`-._    `-.__.-'    _.-'_.-'|
Aug 25 09:19:25 arkos-vagrant redis-server[736]: |    `-._`-._        _.-'_.-'    |
Aug 25 09:19:25 arkos-vagrant redis-server[736]: `-._    `-._`-.__.-'_.-'    _.-'
Aug 25 09:19:25 arkos-vagrant redis-server[736]: `-._    `-.__.-'    _.-'
Aug 25 09:19:25 arkos-vagrant redis-server[736]: `-._        _.-'
Aug 25 09:19:25 arkos-vagrant redis-server[736]: `-.__.-'
Aug 25 09:19:25 arkos-vagrant redis-server[736]: 736:M 25 Aug 09:19:25.471 # Server started, Redis version 3.0.3
Aug 25 09:19:25 arkos-vagrant redis-server[736]: 736:M 25 Aug 09:19:25.472 # WARNING overcommit_memory is set to 0! Background save may fail under low m
Aug 25 09:19:25 arkos-vagrant redis-server[736]: 736:M 25 Aug 09:19:25.472 # WARNING you have Transparent Huge Pages (THP) support enabled in your kerne
Aug 25 09:19:25 arkos-vagrant redis-server[736]: 736:M 25 Aug 09:19:25.472 # WARNING: The TCP backlog setting of 511 cannot be enforced because /proc/sy
Aug 25 09:19:25 arkos-vagrant redis-server[736]: 736:M 25 Aug 09:19:25.472 * The server is now ready to accept connections at /tmp/arkos-redis.sock