Starting traccar service in Ubuntu causing the followoing NullPointerException

Traccar was working yesterday but than too many open file exception appeared, I changed the file limit in security.conf. After that I tried to restart the traccar service and since than this is the exception I am getting when I run these commands:

sudo systemctl start traccar.service

and than check its status:
sudo service traccar status

Jan 07 13:53:11 ip-172-31-45-26 traccar[4426]:         at org.traccar.Main.run(Main.java:152)
Jan 07 13:53:11 ip-172-31-45-26 traccar[4426]:         at org.traccar.Main.main(Main.java:104)
Jan 07 13:53:11 ip-172-31-45-26 traccar[4426]: Caused by: java.lang.NullPointerException
Jan 07 13:53:11 ip-172-31-45-26 traccar[4426]:         at org.traccar.helper.Log.setupDefaultLogger(Log.java:160)
Jan 07 13:53:11 ip-172-31-45-26 traccar[4426]:         at org.traccar.Context.init(Context.java:361)
Jan 07 13:53:11 ip-172-31-45-26 traccar[4426]:         at org.traccar.Main.run(Main.java:110)

This was the Log warning when I tried to increase open file limit:

2019-01-07 12:45:35  WARN: An exceptionCaught() event was fired, and it reached at the tail of the pipeline. It usually means the last handler in the pipeline did not handle the exception. - Too many open files - IOException (...)
2019-01-07 12:45:35  WARN: Too many open files - IOException (...)

You have a problem with configuration file.

Ah, true that. Due to lack of my JAVA expertise I was not able to figure out but I was trying to change timeout value to 5 min using:

<entery key='web.timeout'>300000</entery>

i guess I am not using this correctly than. I removed it and it worked.

My device Heart Beat time is 3 min so I was setting it to 5 min. Bcoz i was having connection limit problem.

Plus, your support is great, really loved the response for an open source software. In past 3 days I had 2 problems and both time you came up with a quick response. Keep it up!

Thanks

I am surprised by number of connections it needs. I have 40 to 50 devices sending data during a day. And the number of connections on my ports increase very rapidly. Although I have set my limit pretty high. But was wondering if may be the connections are not getting timed out properly.

Have you configured connection timeouts?

Well that is when I messed up the config file when i added this line to my config. Is there any mistake in this line?

<entery key='web.timeout'>300000</entery>

I don't see any errors in this particular line, but I don't know why you would change the default value.