How to rename language .mo file?

Rename the *.mo file to wp_pubarch_translate.mo. This is a known issue with the current implementation, and will be fixed in version 3.0.

Thanks for answer @eric but I did it and nothing changed.

Your translation file should be named wp_pubarch_translate-cs_CZ.mo as well.

Thanks I did it. But still no change. I don’t know what is wrong. Ctrl+F5 no working :-/

Can you link to your .mo file so I can grab a copy for testing?

vulicce2289.cz/standard-path…/wp_pubarch_translate-cs_CZ.po

Your server won’t serve that file. It redirects and I can’t see anything.