Image preview doesn't work in Dolphin, but only when using Firefox file selection (ie upload a file to a website, pic the file to upload)

[meven]

@marcatore

I’ve similar problem but seems not Firefox related as my problem is that the image previews are unable for the file saved on a network path (LAN).

That’s completely different. Are talking smb:// or network filesystem ?
For the smb:// case, previews are currently disabled.