Another workaround
...is to set "Windows 7" in
WineHQ Bugzilla – Bug 54460 – WinSCP - rendering issue (missing text) on 'Windows 8.1' (and up)
winecfg
for WinSCP (or for all programs) – the text will appear. This bug is already in Wine Bugtracker:
WineHQ Bugzilla – Bug 54460 – WinSCP - rendering issue (missing text) on 'Windows 8.1' (and up)