ffmpeg "Missing key frame while searching for timestamp" message

[the_steve_randolph]

I have a bunch of MP4 files that I am editing with Adobe Premiere Elements 14 (to chop out unwanted segments) and then using ffmpeg to add chapters and some metadata. Some of those segments are at the beginning of the file, which I suspect may be leading to this error when using ffmpeg:

st: 0 edit list: 1 Missing key frame while searching for timestamp: 0
st: 0 edit list 1 Cannot find an index entry before timestamp: 0.

When I play these converted MP4s in VLC, they seem to be fine. When I Google the message, some people recommend using the "-ignore_editlist 1" switch. But, I can't seem to find any instances where people had some type of problem when the message occurred and then that problem went away with the "-ignore_editlist 1" switch. They acknowledge that there is something called an "edit list", but, I don't find any explanation of what it is or does.

So, what does this message mean, when/where will this reveal itself as a problem, and, what does "ignoring" the editlist accomplish?

Edit: it seems that this message happens when I edit the MP4 with Premiere Elements and chop off a portion of the beginning of the file before the ffmpeg conversion. I can mitigate this by using ffmpeg to chop off part of the beginning, but, I am still interested in finding out what problems this error might cause.