What does this message mean during the test?

While load test is going on I see following kind of messages being printed frequently.

This message means that you have 4 running users but 163676 in the queue, waiting to be started.

What does your injection profile look like?
Which version of Gatling do you use?

I am using Gatling 2.0.0-M3a
This is the load I have specified in my simulation

rampRate(1 usersPerSec) to (120 usersPerSec) during(15 minutes), constantRate (120 usersPerSec) during (240 minutes)

Could you upgrade to current snapshot, please?
github.com/excilys/gatling/wiki/Continuous-Integration

github.com/excilys/gatling/wiki/Gatling 2

Version 2.0.0-SNAPSHOT?

I have been running my test with different loads with 2.0.00M3a. Are the results from both the version comparable or is it better to rerun those loads with the this snapshot version?

Thanks for your continuous help!

Your results are a bit weird, like some messages/virtual users being lost.
We’ve fixed some similar bugs since releasing 2M3a.

Okay…then I will rerun my tests. The version is to be used is 2.0.0-SNAPSHOT, is that correct?

Yep.
Beware of properly checking the migration guide: https://github.com/excilys/gatling/wiki/Gatling-2