Hi,
as the title say, when I creat a new BP or move/copy it(or other asset) to another folder, UE4 will create a 1kb file in the old folder. You can see it in windows explore.
and these 1kb file sometime will popup a error log on project opened.
No its not actually. The editor creates a ghost file which is an object redirector. Its there to keep references and links. If you shutdown your editor and start backup, try running “FixUp Redirectors” on the folder where you moved it from. That should clean any redirectors that are still there. =)