[dev] ERROR: MIME::Words: unexpected case:

Hello, How to deal with such message. Attachment didn't pass through. Wide character in print at /opt/otrs/Kernel/System/Log/File.pm line 58. Wide character in print at /opt/otrs/Kernel/System/Log/File.pm line 58. MIME::Words: unexpected case: (Brak mo??liwo?›ci zaksiÄ™gowania PZK32 54193.doc) pos 0 Please alert developer.