Thank you for your reply.
I have used the updated .pot file, but it hasn’t solved the problem. Some texts which are included in the file (f.e. “Home” for the home page) appear in Polish, and some still in English (“Read More”), although I have translated them in the file. Moreover, some expresssions are not included in your file (“Uncategorized”. “Sample Page”).
The process you have described on http://themonic.com/how-to-translate-iconic-one-pro-to-your-language/ simply doesn’t work.
Additionally, when I replace the original WordPress pl_PL files in the wp-content/languages folder with the pl_PL file created from your iconic-one-pro-pot file, I lose the original WordPress translations.
Could you please review the whole process of adding languages, and describe it in more detail?
Thank you in advance!