Internal editor hangs on closure

Something strange started happening today.
Open a remote file in the internal editor and close it again. Editor and WinSCP hangs! (I have to kill the process)

I was running an older version 4 WinSCP, so I upgraded to 5.7.5 but the problem still occurs.

It doesn't always happen right away - sometimes on the 2nd or 3rd file opened. I'm not editing or saving anything, just closing the editor window.

I tried session logging, but it's not showing anything unusual. The last entry is just the "Transfer done" message for the file I opened.

(Using Commander interface on Win 7.)

Thanks for your report.
I have sent you an email with a debug version of WinSCP to address you have used to register on this forum.

Thanks, I tried the debug version, but the problem doesn't happen with that!

Tried regular 5.7.5 again and it's still happening.
As I mentioned, the log file from that doesn't really show anything.

OK, I've sent you another build.

Thanks Martin,
I e-mailed you a log file. I hope it helps.

Thx.