Hello this is K.
Sometime in October of 2020, the file debug.log started appearing unexpectedly on the desktop.
The culprit seems to be the new Microsoft Edge (Chromium and Google Chrome).
This is what the file contains:
(The first numbers indicate date and time.）
[1010/224820.826:ERROR:settings.cc(430)] Settings version is not 5
Or
[1022/163347.329:ERROR:directory_reader_win.cc(43)] FindFirstFile: Path not found. (0x3)
Although deleting the file will not affect your computer, the debug file may reappear again. Until Microsoft Edge/Google Chrome fixes the issue, there is no way to prevent the file from appearing on the desktop. It would be best to wait for the new Windows Update.
Postscript: The file no longer appears on the desktop so this must have been fixed in
this month’s update (not the OS build update). If you have not done your updates,
do so manually before deleting your debug file. I am currently still using build 1909.