Can anyone help me this error?

I was join realistic ground battle and I have kicked out and this message show on screen. Can anyone help me please?

Just means that you lost connection to the server while it was loading. Happened to me a couple times yesterday so probably a server issue. Nothing major though so you shouldnt have to worry about it.

can this fix?

Can you still join a match right now? Or is it showing it everytime?

happened to me twice today you should be fine

Yeah. Should just be a once in a blue moon thing at the moment. It will get resolved soon i am sure.

It showing everytime I join the match.

In that case, most likely on your end. Close the game, reconnect your internet, and do a file check.