Question - Allow incomplete

[RoeiGanor]

While capturing traffic I noticed that goreplay doesn't capture the responses even though they are present on tcpdump.
After investigating, I discovered that adding --input-raw-allow-incomplete fixed the issue.
What does it mean that the responses are incomplete, how can I test it using Wireshark and is there any, more permanent solution to fix the "incompletion" of the responses?

Thanks in advance.