This error indicates that winscp.exe did not receive an answer from winscp.com in time.

Most commonly this happens when winscp.com has redirected output to a stream with limited buffer. If the stream is not being read from, the buffer gets eventually filled and winscp.com hangs, when trying to write into it.

In turn the above most commonly happens when winscp.com is run from another program (such as .NET code), which redirect its output into stream. If the program then e.g. waits for winscp.com to finish without reading from the stream, the winscp.com eventually hangs, never finishing.

See example of .NET or WSH code dealing with the problem.