Poolverine: I assume you are trying to submit an alternate title something like Dvanásť rozhnevaných mužov (1957) for Slovakia, but it's not accepted because Slovakia was not an independent country in 1957.
The way to deal with this is to substitute the first year when Slovakia was an independent country that 12 Angry Men was in distribution in the country under the title Dvanásť rozhnevaných mužov. That would probably make it Dvanásť rozhnevaných mužov (1993) instead.
I don't really understand the point of requiring years for alternate titles, since they don't display, but using 1993 as the year after the title should solve your problem.
(On a separate note, it looks like you need to use the attribute original ISO-LATIN-2 title for the "t with hacek" character, ť, to be accepted. I tried to test this using the standard attribute imdb display title and the character was not accepted that way, but changing the attribute allowed the character to be accepted.)