"Working…" is displayed forever

I’m trying to import from qTranslate to WPML with this plugin.
I disabled qTranslate, enabled this plugin and WPML as instruction says.
Then when I clicked on “Start” button, “Working…” message is displayed next to the button and nothing happened even I waited for the whole night.
My website is showing nothing, it’s just a white screen.

Is there any way that I can solve this issue?

https://www.ads-software.com/extend/plugins/qtranslate-to-wpml-export/