Steps to reproduce (tested this only on ssh connection):
1. Create some directory on server and enter it in WinSCP, for example
2. Remove that directory on server by some other method (I use Kitty, a fork of Putty)
3. Now in WinSCP try going to parent directory, you will receive an error
Cannot get real path for '/abc/..'.
No such file or directory.
Error code: 2
Error message from server: No such file
It's probably related to my other bug report, I suspect that going to parent directory forces WinSCP to refresh current directory (which is a really stupid thing to do...)