This is generally caused by a failing network switch, card, or router.
Replacement or the bad component is the solution.

It has also been caused by anti-virus / anti-spyware programs aggressively
checking every file. This causes system slowness to the point where this
message appears. We suggest that you set your av software programs to skip
.DBF, .CDX, .FTP and .TXT files as a test should you receive this message.