Traccar server stopped connecting

Server was working well without any issues till now, i can't seem to get the server to start and "connect" as it would report on the logs, it just stalls after starting server

017-04-11 17:00:12 INFO: Character encoding: UTF-8 charset: UTF-8
2017-04-11 17:00:12 INFO: Version: 3.9-SNAPSHOT
2017-04-11 17:00:23 INFO: Starting server...
2017-04-11 17:11:52 INFO: Shutting down server...
2017-04-11 17:12:21 INFO: Operating system name: Linux version: 4.4.0-47-generic architecture: amd64
2017-04-11 17:12:21 INFO: Java runtime name: Java HotSpot(TM) 64-Bit Server VM vendor: Oracle Corporation version: 25.111-b14
2017-04-11 17:12:21 INFO: Memory limit heap: 494mb non-heap: 0mb
2017-04-11 17:12:21 INFO: Character encoding: UTF-8 charset: UTF-8
2017-04-11 17:12:21 INFO: Version: 3.9-SNAPSHOT
2017-04-11 17:12:31 INFO: Starting server...

You are looking at the wrong log file.

which is the right log to look at?
the latest wrapper log has this:

WARN org.eclipse.jetty.servlet.ServletHandler - /api/socket
FINEST|19776/0|Service traccar|17-04-11 18:37:05|java.lang.NullPointerException
FINEST|19776/0|Service traccar|17-04-11 18:37:05|	at org.traccar.api.AsyncSocketServlet$1.createWebSocket(AsyncSocketServlet.java:37)
FINEST|19776/0|Service traccar|17-04-11 18:37:05|	at org.eclipse.jetty.websocket.server.WebSocketServerFactory.acceptWebSocket(WebSocketServerFactory.java:166)
FINEST|19776/0|Service traccar|17-04-11 18:37:05|	at org.eclipse.jetty.websocket.server.WebSocketServerFactory.acceptWebSocket(WebSocketServerFactory.java:153)
FINEST|19776/0|Service traccar|17-04-11 18:37:05|	at org.eclipse.jetty.websocket.servlet.WebSocketServlet.service(WebSocketServlet.java:151)
FINEST|19776/0|Service traccar|17-04-11 18:37:05|	at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
FINEST|19776/0|Service traccar|17-04-11 18:37:05|	at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:812)
FINEST|19776/0|Service traccar|17-04-11 18:37:05|	at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:587)
FINEST|19776/0|Service traccar|17-04-11 18:37:05|	at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:221)
FINEST|19776/0|Service traccar|17-04-11 18:37:05|	at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1127)
FINEST|19776/0|Service traccar|17-04-11 18:37:05|	at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:515)
FINEST|19776/0|Service traccar|17-04-11 18:37:05|	at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:185)
FINEST|19776/0|Service traccar|17-04-11 18:37:05|	at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1061)
FINEST|19776/0|Service traccar|17-04-11 18:37:05|	at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:141)
FINEST|19776/0|Service traccar|17-04-11 18:37:05|	at org.eclipse.jetty.server.handler.HandlerList.handle(HandlerList.java:52)
FINEST|19776/0|Service traccar|17-04-11 18:37:05|	at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97)
FINEST|19776/0|Service traccar|17-04-11 18:37:05|	at org.eclipse.jetty.server.Server.handle(Server.java:499)
FINEST|19776/0|Service traccar|17-04-11 18:37:05|	at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:311)
FINEST|19776/0|Service traccar|17-04-11 18:37:05|	at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:257)
FINEST|19776/0|Service traccar|17-04-11 18:37:05|	at org.eclipse.jetty.io.AbstractConnection$2.run(AbstractConnection.java:544)
FINEST|19776/0|Service traccar|17-04-11 18:37:05|	at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:635)
FINEST|19776/0|Service traccar|17-04-11 18:37:05|	at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:555)
FINEST|19776/0|Service traccar|17-04-11 18:37:05|	at java.lang.Thread.run(Thread.java:745)

Both logs look fine. What exactly doesn't work?

The next entry log i would expect from the server log was that the server was connected then it starts receiving gps locations from the device.
The clear indicator is that the server is no longer receiving positions from the device, as per the logs

If server is working and there is nothing in the logs, it means that the problem is with your device(s) or network, not with the server.

Thanks for the help Anton, I just changed the port number to 5006 then back to 5013 and seems to work now