Copy Files step limit?

[Too_Tall_Crown_Victoria]

I have been converting our dos command xcopy steps to use the built in Copy Files step. However, I have found that on very large copies (~3GB, 35K files, 4500 directories) it fails after a while with an error saying it cannot copy a file. When I try to rerun it, it fails sometimes on that file, other times on other files. I had to go back to the dos command xcopy to get it work.

I can provide a sample zip but it will be quite large to truly reproduce the issue.