0.98.2: rename sometimes fails

[Devil]

XnView: MP 0.98.2 - 64 bit
OS: Windows 10 64bit

Sometimes the renaming of file fails for no reason.

To reproduce:
Random
I open file via association (png or jpg), then press F2 to rename file, modify the editbox and press Enter. Sometimes the file is NOT renamed and no message is showed indicating it failed. There is no reason to fail - the file is not accessed by any other program. When this happeneds and a do F2, edit and Enter again, it works. When it fails the filename in title is not changed.
One way to reproduce it is to open big image file and immediately press F2, type something and press Enter - this fails to rename every time - probably because the file is still loading when I press the F2. But sometimes it fails even when I try to rename after few seconds (but I may do zoom for instance just before it ...)

Actual behaviour (bug): Silently fails with no message and indication that the rename was not done.

Expected behaviour: File is renamed or error is displayed if it can't be ranemed

[xnview]

i've reproduced one time only, the size of picture file is high?

[Devil]

I've done some more research:
It doesn't really matter how big is the picture, only how long the Xnview is starting. I can easily replicate it on 5kB png.
It's enough just run associated image and press F2 before the form finishes loading (just, press enter and F2 right after). If the rename dialog is initializing before the complete load of image is done, it doesn't matter if you then wait long before pressing enter, it will not rename the file.