The bane of many an editor. I encounter this bug at least once a day. If this happens in the middle of a render, the entire thing fails. (Thank Adobe for smart rendering, at least!)
The best workaround I've been able to come up with, is to ALWAYS render timeline previews. I use cineform, and so the final, smart render, is very fast.
Here is a long forum thread about it. This bug has been a problem for many years:
https://forums.adobe.com/thread/2171535This is Unique ID 160 on my Premiere problems spreadsheet:
https://docs.google.com/spreadsheets/d/1dVJb7kI_ZETLavrplfARgn9gL8HUpvkq6A0jCPxqA3w/edit#gid=1133868...