Rogue file causes backup to fail

[ChrisZoom]

I do a backup on my Linux system by a simple copy of my files. It halts when it gets to two files, saying they can't be copied, they are:

com.zoom.ipc.assistantapp__req

com.zoom.ipc.assistantapp__res

They are empty and I'll take a risk and delete them, however if they get recreated the same will happen next time I do a backup. What are they and how can I stop them getting created or ensure they are created properly?