Probably. You should probably look further up the log and ^F search for download.
If the file is not found in /home/USER/snap/easy-installer/common/sources/OnePlus7Pro/ it would imply there was a downloading error, which should stop the process and be reported.
easy-installer ← you could forum search this tag; has had a run of errors including this – maybe a change of code is hiding a similar error for you, idk.
We are awaiting a “new” Easy Installer