From Wikipedia.
I believe the bolded may be a case of Wiki vandalism. The source cited does not appear to ban him from entry to the EU; I'm not actually sure what it means.
It's a blanket ban on senior officials of the Transnistrian government in 2005 (which included Shevchuk, Smirnov, and Kaminsky, among others) from entering the European Union until the government stopped its oppression of schools that taught Latin-alphabet Moldovan (as they do in Moldova) rather than Cryllic-alphabet Moldovan (like they prefer in Transnistria). I don't know how serious these problems were or whether the ban still exists. I also don't know what Shevchuk's role in it was; if you can trust his wikipedia article, he sounds like a bit of a reformer.