This was reported by the Speaker of the Ukrainian Foreign Ministry Marian Bez.
The speaker's notification says that the ambassador must arrive immediately to give explanations about these actions of the Polish Foreign Ministry. Betza hopes that the ambassador will be able to adequately explain the actions of the Polish head Vashchikovsky and once again do not give rise to a conflict between the two states.
Recall that Sheremet was in the so-called - "black list" Vashchikovsky, which contains the names of people in anti-Polish views, which are banned from entering the country.
As reported in URA-Inform, Sheremety has a Schengen visa issued by Germany, and it is obvious that the credibility of international documents is much higher than the national ones.