_x() not recognised

Actually, it seems there is a broader bug, not all __() are recognised as well, I have this in code, only first __() in each function argument is recognised, but not second.

		<?php
		output_row('uvod_slika.jpg', __('Ilustracija', 'virtual-exhibition'), __('Uvod', 'virtualna-izlozba'), 'restaurirani-predmeti-iz-zbrike-namjestaja-muzeja-mimara', false);
		output_row('fotelja_naslovna.jpg', __('Fotelja', 'virtual-exhibition'), __('Odabir iz fundusa', 'virtualna-izlozba'), 'fundus', true);
		?>

i.e.
__(‘Ilustracija’, ‘virtual-exhibition’) is recognised, while __(‘Uvod’, ‘virtualna-izlozba’) is not

There is no bug here. Your two examples have separate text domains. A POT file should contain one text domain only. The sting extractor will recognise one text domain only.

Try reading my help page for plugin and theme authors: https://localise.biz/wordpress/plugin/authors

Yes, I also concluded that was the problem. I’ll investigate again for the _x() though.

_x is recognised. There is no problem extracting strings from this as long as the text domain matches what’s being extracted and all arguments are string literals.

I can confirm that _x() also works, it was probably domain problem.