Tcp null pointer exception error

On Ubuntu, talking to my Elk security system using the tcp/udp binding. I’m not sure if it is an Elk issue, or just a generic thing I am doing wrong.

In my elk.items I have

String ElkString "Elk String [%s]" { tcp=">['']"}

And in my tcp.cfg, I have


For the most part, it seems like everything is working, but I get a ton of errors in the log, which is worrisome.

Every time OH receives a message from the security system, I get the message and I can parse it, but I also get this error message:

2018-08-22 17:19:00.710 [ERROR] [b.core.service.AbstractActiveService] - Error while executing background thread TCP Refresh Service
java.lang.NullPointerException: null

It doesn’t seem to be related to any rules or anything else that I am doing because I can delete them, but I still get the error message.

Any ideas? Or should I just ignore them?