Cannot focus a disabled or invisible window - Vcl::Comctrls::TToolButton::

<Try to describe precise steps that lead to the problem (where do you click, what keys do you press, what do you see, etc.)>
<If relevant, consider attaching a session log file or a screenshot)>
The VPN connection behind got disconnected while trying to change the directory.

WinSCP 5.21.5

Error message:
Cannot focus a disabled or invisible window

Stack trace:
(0023ECB6) Vcl::Comctrls::TToolButton::

The problem happens rarely. I cannot reproduce it.